For each of the following equations, show that the given value of x is a solution of the equation by direct substitution.

a) x = 4/3, Equation: 3x^2 + 5x - 12=0

b) x=1 + square root 6 , Equation: x^2 - 2x-5=0

c) x= 1 + 2i, Equation: x^2 - 2x+5=0

Answers

Answer 1

a.

The value x = 4/3 is a solution of the equation 3x² + 5x - 12 = 0

Since the equation is 3x² + 5x - 12 = 0, if x = 4/3, is a solution, substituting x = 4/3 into the equation will make the equation will make the left hand side equal zero.

So, 3x² + 5x - 12 = 0

Substituting x = 4/3, we have

3(4/3)² + 5(4/3) - 12

= 3(16/9) + 20/3 - 12

= 16/3 + (20 - 12 × 3)/3

= 16/3 + (20 - 36)/3

= 16/3 - 16/3

= 0

So, x = 4/3 is a solution of the equation 3x² + 5x - 12 = 0

b.

The value x = 1 + √6 is a solution of the equation x² - 2x - 5 = 0

Since the equation is x² - 2x - 5 = 0, if x = 1 + √6, is a solution, substituting x = 1 + √6 into the equation will make the equation will make the left hand side equal zero.

So, x² - 2x - 5 = 0

Substituting x = 4/3, we have

x² - 2x - 5 = (1 + √6)² - 2(1 + √6) - 5

= (1² + 2√6 + (√6)²) - 2 - 2√6) - 5

= 1 + 2√6 + 6 - 2 - 2√6) - 5

= 2√6 + 6 + 1 - 2√6) - 5 - 5

= 2√6 + 7 - 2√6) - 7

=  2√6 - 2√6 + 7 - 7

= 0 + 0

= 0

So, x = 1 + √6 is a solution of the equation x² - 2x - 5 = 0

c.

The value x = 1 + 2i is a solution of the equation x² - 2x + 5 = 0

Since the equation is x² - 2x + 5 = 0, if x = 1 + 2i, is a solution, substituting x = 1 + 2i into the equation will make the equation will make the left hand side equal zero.

So, x² - 2x + 5 = 0

Substituting x = 1 + 2i, we have

x² - 2x + 5 = (1 + 2i)² - 2(1 + 2i) + 5

= (1² + 2(2i) + (2i)²) - 2 - 4i + 5

= 1 + 4i - 4 - 2 - 4i + 5

=  4i + 1 - 4 - 2 - 4i + 5  

= 4i - 5 - 4i + 5  

= 4i - 4i + 5 - 5

= 0 + 0

= 0

So, x = 1 + 2i is a solution of the equation x² - 2x + 5 = 0

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Related Questions

Help please tell me how to do this I don't know.

Answers

Answer:

Where are the values I can't read your qn properly my friend may the lord assist you

five friends get together to have a thanksgiving dinner. roger, ted, tom, pam, and donna brought (in no particular order) turkey, salad, dressing, peas, and potatoes. each item was brought on a different colored plate (no particular order) white, purple, black, green, and pink.
- no food begins with the same letter as the name of the person who brought it
- the dressing was not brought by tom or pam
- the person who brought the potatoes and the person who brought the green plate both have names that begin with the same letter
- neither rogers plate nor teds plate was purple and the peas were also not brought on the purple plate
- toms food and the food on the pink plate are not peas or potatoes
- donna did not bring the black plate

try to determine the kind of food each person brought and what color plate it was on

Answers

Pam carried turkey on a black plate, Tom carried salad on a purple plate, Roger carried dressing on a pink plate, Donna carried peas on a white plate, and Ted carried potatoes on a green plate.

To determine the kind of food each person brought and what color plate it was on, the following reasoning must be performed:

- no food begins with the same letter as the name of the person who brought it  

Turkey = Roger, Pam or Donna Salad = Roger, Ted, Tom, Pam or Donna Dressing = Roger, Ted, Tom or Pam Peas = Roger, Ted, Tom or Donna Potatoes = Roger, Ted, Tom or Donna  Green plate = Roger, Ted, Tom, Pam or Donna Purple plate = Roger, Ted, Tom, Pam or Donna White plate = Roger, Ted, Tom, Pam or Donna Black plate = Roger, Ted, Tom, Pam or Donna Pink plate = Roger, Ted, Tom, Pam or Donna

- the dressing was not brought by Tom or Pam  

Turkey = Roger, Pam or Donna Salad = Roger, Ted, Tom, Pam or Donna Dressing = Roger or Ted Peas = Roger, Ted, Tom or Donna Potatoes = Roger, Ted, Tom or Donna  Green plate = Roger, Ted, Tom, Pam or Donna Purple plate = Roger, Ted, Tom, Pam or Donna White plate = Roger, Ted, Tom, Pam or Donna Black plate = Roger, Ted, Tom, Pam or Donna Pink plate = Roger, Ted, Tom, Pam or Donna

- the person who brought the potatoes and the person who brought the green plate both have names that begin with the same letter  

Turkey = Roger, Pam or Donna Salad = Roger, Ted, Tom, Pam or Donna Dressing = Roger or Ted Peas = Roger, Ted, Tom or Donna Potatoes = Ted or Tom  Green plate = Ted or Tom Purple plate = Roger, Ted, Tom, Pam or Donna White plate = Roger, Ted, Tom, Pam or Donna Black plate = Roger, Ted, Tom, Pam or Donna Pink plate = Roger, Ted, Tom, Pam or Donna

- neither Roger's plate nor Ted's plate was purple and the peas were also not brought on the purple plate  

Turkey = Roger, Pam or Donna Salad = Roger, Ted, Tom, Pam or Donna Dressing = Roger or Ted Peas = Roger, Ted, Tom or Donna Potatoes = Ted or Tom  Green plate = Ted or Tom Purple plate = Tom or Donna White plate = Roger, Ted, Tom, Pam or Donna Black plate = Roger, Ted, Tom, Pam or Donna Pink plate = Roger, Ted, Tom, Pam or Donna

- Tom's food and the food on the pink plate are not peas or potatoes  

Turkey = Pam Salad = Tom Dressing = Roger Peas = Donna Potatoes = Ted  Green plate = Ted or Tom Purple plate = Tom or Donna White plate = Roger, Ted, Tom, Pam or Donna Black plate = Roger, Ted, Tom, Pam or Donna Pink plate = Roger or Pam

- Donna did not bring the black plate  

Turkey = Pam Salad = Tom Dressing = Roger Peas = Donna Potatoes = Ted  Green plate = Ted or Tom Purple plate = Tom or Donna White plate = Roger, Ted, Tom, Pam or Donna Black plate = Roger, Ted, Tom or Pam Pink plate = Roger or Pam

- the person who brought the potatoes and the person who brought the green plate both have names that begin with the same letter  

Turkey = Pam Salad = Tom Dressing = Roger Peas = Donna Potatoes = Ted  Green plate = Ted Purple plate = Tom or Donna White plate = Roger, Tom, Pam or Donna Black plate = Roger, Tom or Pam Pink plate = Roger or Pam

- neither Roger's plate nor Ted's plate was purple and the peas were also not brought on the purple plate  

Turkey = Pam Salad = Tom Dressing = Roger Peas = Donna Potatoes = Ted  Green plate = Ted Purple plate = Tom White plate = Roger, Pam or Donna Black plate = Roger or Pam Pink plate = Roger or Pam

- Tom's food and the food on the pink plate are not peas or potatoes  

Turkey = Pam Salad = Tom Dressing = Roger Peas = Donna Potatoes = Ted  Green plate = Ted Purple plate = Tom White plate = Donna Black plate = Pam Pink plate = Roger

Therefore, Pam carried turkey on a black plate, Tom carried salad on a purple plate, Roger carried dressing on a pink plate, Donna carried peas on a white plate, and Ted carried potatoes on a green plate.

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Value of x 2(x-4)=10

Answers

Answer:

x=9

Step-by-step explanation:

Order of operations and cross
reduce:
I got 20/3 but I think I’m wrong

Answers

Answer:

130/81

simplified: 1 49/81

Step-by-step explanation:

I did the math

what is the reason for line 3??

Answers

Answer:

SAS similarity

Step-by-step explanation:

LO and LP are proportional to LN and LM, as shown by:

[tex]\frac{LO}{LN} =\frac{LP}{LM}[/tex]

Because these are equal, both pairs of corresponding lines have the same scale factor and are proportional as a result. The angle between them is congruent due to the reflexive property as given, and with 2 pairs of proportional sides including the angle, ΔLMN is similar to ΔLPO by the SAS similarity postulate

Which of the following inequality’s matches the graph? A: x ≤ 5 B: x ≥ 5 C: y ≤ 5 D: y ≥ 5 what is the answer



Answers

Answer: Choice A

[tex]x \le 5[/tex]

========================================

Explanation:

Any point in the shaded purple region has an x coordinate that is 5 or smaller. So we go for [tex]x \le 5[/tex]. Either x = 5 or x < 5. The boundary line is solid to indicate that points on the boundary are included in the solution set.

Please help me ASAP this has limited time olease

Answers

Answer:

x= 67

Step-by-step explanation:

Angle CGE makes a 23 degree angle, and makes a 90 degree angle with CGB.

By subtracting 90 and 23, you get 67 degrees for the angle EGB.

Since angle EGB and angle AGF are vertical angles, they are the same. So, x would equal 67.

Answer:

x = 67°

Step-by-step explanation:

Solving for x

We know that AGC is a right angle, thus AGD has to be a right triangle as well. Angle CGE is 23°, which would mean that FGD is also 23°.

90°-23°=67°

Roberto bikes for 5.2 hours and covers a distance of 49.4 miles. Eileen bikes for 2.5 hours and covers a distance of 20.5 miles.
Assuming both Roberto and Eileen bike at a constant speed, who was biking faster and by how much? Select from the drop down menus to correctly answer the question. Choose... bikes faster than Choose... by Choose... mi/h.

Answers

Answer:

Roberto bikes faster than Eileen by 1.3 mi/h

Step-by-step explanation:

Roberto bikes at 49.4/5.2=9.5 mi/h

Eileen bikes at 20.5/2.5=8.2 mi/h

9.5-8.2=1.3

So Roberto bikes faster than Eileen by 1.3 mi/h

someone help me with these 2 questions asap!!

Answers

Step-by-step explanation:

we would have needed only one corresponding side length. because for similar triangles all corresponding lines (like sides but also heights and so on) would be related in size by using the same scaling factor.

going from the large to the small triangle : what do I need to multiply the large side length with to get the small one ?

27 × x = 9

x = 9/27 = 1/3

that is the scale factor.

solve for x, x-c=r+d/y

Answers

Answer:

D

Step-by-step explanation:

x - c = (r + d)/y                   for x

x = (r +d)/y + c          common denominator : (c/1) (y/1)  = yc

x = (r + d)/y + yc

x =   (yc + r + d)/ y                              


You want to buy some noodles. A 7-ounce package costs $2.24. A 12-ounce package costs $4.08.
An 18-ounce package costs $5.58. Which package is the best buy?

Answers

2.24 divided by 7 is 0.32

And 5.58 divided by 18 is 0.31

So 5.58 is cheaper

The length of one of the sides of a triangle is equal to 1m, the measurement of adjacent angles are 30º and 45º. What are the lengths of the other sides of this triangle?

Answers

Thr length of one of the sides of a triangle is equal to 1m, the mesurement of adjacent....... 45, 30 is lengths of the both side triangle.

THANK YOU

Robert has 4 times as many pennies as he does nickels. If Robert has $1.44 worth of pennies and nickels, how many nickels does he have?​

Answers

9514 1404 393

Answer:

  16 nickels

Step-by-step explanation:

Robert can group his coins into groups consisting of 1 nickel and 4 pennies. The value of each group is 9¢, so the number of groups Robert can make is ...

  $1.44/$0.09 = 16 . . . groups

Since there is 1 nickel in each group, Robert has 16 nickels.

Answer:

16

Step-by-step explanation:

b) Complete the table to show the total amount of calories Mary will burn for
cycling and running for 0, 10, 15, and 30 minutes. Show and explain your work.
Minutes (m)
Total Calories Burned (C)
0
10

Answers

For 0 minutes she can burn 0 calories

For 10 minutes she can burn 20-40 calories

For 15 mins she can burn 40-60 calories

For 30 minutes she can burn 140-295 calories

I hoped this helped!

Have a great day/night! :)

Gul can run 800 meters in 139 seconds.About how long would it take her to run 6 times far if she runs at the same speed? Choose the best estimate.

Answers

Answer:

834 seconds or 13 minutes and 54 seconds

Step-by-step explanation:

139 x 6 = 834

.Sort the numbers based on the number of significant figures they have.

Drag each tile to the correct location.

1,230
155.6
200
1,245
8.88
22
136
8.880
0.01
20
20.

Answers

Let's check the significant figures one by one

[tex]\\ \sf\longmapsto 1,230=3[/tex]

[tex]\\ \sf\longmapsto 155.6=4[/tex]

[tex]\\ \sf\longmapsto 200=1[/tex]

[tex]\\ \sf\longmapsto 1245=4[/tex]

[tex]\\ \sf\longmapsto 8.88=3[/tex]

[tex]\\ \sf\longmapsto 22=2[/tex]

[tex]\\ \sf\longmapsto 136=3[/tex]

[tex]\\ \sf\longmapsto 8.880=3[/tex]

[tex]\\ \sf\longmapsto 0.01=1[/tex]

[tex]\\ \sf\longmapsto 20=1[/tex]

One Significant figure - 200, 0.01, 20

Two Significant figures- 22, 20.

Three Significant figures- 1,230, 8.88, 136

Four Significant figures- 155.6, 1,245, 8.880

PLATO

The points (-1, 4) and (2, 9) lie on a line.
What is the slope of the line?

Answers

Answer:

[tex]\displaystyle m = \frac{5}{3}[/tex]

General Formulas and Concepts:

Pre-Algebra

Order of Operations: BPEMDAS

Brackets Parenthesis Exponents Multiplication Division Addition Subtraction Left to Right

Algebra I

Coordinate Planes

Coordinates (x, y)Slope Formula: [tex]\displaystyle m = \frac{y_2 - y_1}{x_2 - x_1}[/tex]

Step-by-step explanation:

Step 1: Define

Identify

Point (-1, 4)

Point (2, 9)

Step 2: Find slope m

Simply plug in the 2 coordinates into the slope formula to find slope m.

Substitute in points [Slope Formula]:                                                              [tex]\displaystyle m = \frac{9 - 4}{2 + 1}[/tex][Order of Operations] Simplify:                                                                        [tex]\displaystyle m = \frac{5}{3}[/tex]

A local hamburger shop sold a combined total of 387 hamburgers and cheeseburgers on Thursday. There were 63 fewer cheeseburgers sold than hamburgers. How many hamburgers were sold on Thursday?

Answers

Answer:

350 hamburgers

Step-by-step explanation:

Let x = the number of hamburgers sold

Let x - 53 = the number of cheeseburgers sold

x + x - 53 = 647

2x = 700

x = 350 hamburgers

describe how you know this is a proportional relanshoships

Answers

Answer:

don't see the relationship, but if it's a proportional relationship it should have the same result every time you divide the x by the y or vice versa.

If 5 measures 110 what is the measure of 2?

A) 55
B) 70
C) 110
D)160

Answers

The answer is C) 110. This is because they are corresponding angels which means they are congruent

Samantha has 7/3 cups of ice cream to make milk shake.Each shake uses 1/8 cup of ice cream. How many milk shakes can she make?

Answers

18 milkshakes
Hope this helps

Which equation is an identity?
A)
3x + 4 = 5x - 1
B)
2x + 3 = 2x + 4 - 1
C)
5x = 10
D)
- 3x + 1 = -3x - 5

Answers

Answer:

B) 2x + 3 = 2x + 4 - 1

Step-by-step explanation:

A) 3x + 4 = 5x - 1

2x = 5

x = 2/5

B) 2x + 3 = 2x + 3

True

C) 5x = 10

x = 2

D) -3x + 1 = -3x - 5

False

I need answers 1 through 5 please

Answers

Answer:

1) first & last option

2) x=10

3) x=15

4) acute, acute, obtuse. right

5)

Step-by-step explanation:

(8)^2+(6)^2=(x)^2

64+36=x^2

square root of 100= square root of x^2

x= 10

pls help with 4 4/7 -

see attached pic​

Answers

We cannot see your picture but it should be 8/8

Rewrite the expression with
parentheses to equal the
given value.
3x 8-5 + 3

value: 12

Answers

3 x (8 - 5) + 3

Parentheses go first here, so 8 - 5 is 3.
Multiplication goes next, so 3 x 3 is 9.
Addition goes last, so 9 + 3 is 12.

Of the following points name all that lie on the same vertical line (3,-7)(-5,3)(3,-3)(3,-9)

Answers

Answer:

(-3,9)

Step-by-step explanation:

HOPE THIS HELPSSSSSS!!!!

Help help math math help help

Answers

Answer:no they are not

Step-by-step explanation:

As all angles are 60∘ each and given all sides are equal then it can be said as congruent.

Answer:

no

Step-by-step explanation:

I really need help this is due in a little bit and I need to finish

Answers

Answer:

The correct form is [tex]y = -2x + 24[/tex]

Step-by-step explanation:

First we need to interpret the equation of Nolan.

The [tex]y[/tex] means the current value in the bank accountThe [tex]x[/tex] means the past days-2 means that spend each dayand 12 the initial amount in the bank

How you can see the initial amount in the bank is incorrect because Nolan started with 24 instead of 12.

So the correct form of the equation is:

[tex]y = -2x + 24[/tex]

Determine the slope and y-intercept of a line that passes through the points (2, 4) and (–4, 1).
m = [ A. –2.5 , B. –1.5 , C. 0.5 ]
b = [ A. 3, B. 7, C. 9 ]

Answers

Answer:

hhhhhhhhhhhhiiiiiiiii

Find the value of y when x=-4
4. 1/3y=2(x-1/6) 5. -6x-y=17.75

Answers

Answer:

1/3y=2(-4-1/6)

The first one answer is y=-25

-6×-4-y=17.75

The second answer is y=6.25

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