Solve −3x2 + 30x − 90 = 0

Answers

Answer 1

Step-by-step explanation:

so, it is a quadratic equation :

-3x² + 30x - 90 = 0

the first thing we can do is divide by 3

-x² + 10x - 30 = 0

remember, the formula to solve and find the 2 solutions is

x = (-b ± sqrt(b² - 4ac))/(2a)

in our case here

a = -1

b = 10

c = -30

x = (-10 ± sqrt(100 - 4×-1×-30))/-2 =

= (-10 ± sqrt(100 - 120))/-2 = (-10 ± sqrt(-20))/-2 =

= (-10 ± sqrt(4×5)i)/-2 = (-10 ± 2×sqrt(5)i)/-2 =

= 5 ± -sqrt(5)i

x1 = 5 - sqrt(5)i

x2 = 5 + sqrt(5)i

remember, i = sqrt(-1), a complex number.


Related Questions

which option would be correct?

Answers

Answer:

similar by angle angle similarity property.

Step-by-step explanation:

they have the right angles, and then the two vertical angles.

:))

Harold and his brother collected 2019 cans a 1-year period. Each boy collected the same number of cans. About how many cans did each boy collect? Explain how you found your answer.​

Answers

Answer:

1008.5 cans

Step-by-step explanation:

2019/2=1008.5

if you wanted per day, 1008.5/365=2017/730

Suppose you plan to take a survey of Math 146 students asked about their overall grades at CBC. 22 students were surveyed, and it was found that the average GPA of the 22 sampled students was a 3.2, with a standard deviation of 0.9 points. Suppose you want to re-sample the population to reduce the margin of error. If you plan to calculate a 90% confidence interval for the true mean GPA of Math students, how many samples would be necessary to reduce the margin of error to 0.2 points?

Answers

Step-by-step explanation:

we have the data set given below here and using it, we want to find the sample mean X. Bar, the sample standard deviation S. And constructed 99% confidence interval for the population we knew, assuming the population is normally distributed. So since we have this data we can find expire and s using the appropriate definitions expire, is that some of the data divided by n 2.353 and s. Is the square root of the sum of deviations of the mean square divided by n minus one. In this case 1.3 Now with X. Bar and sample standard deviation S, we can use a student's t distribution to construct this confidence interval. So we can identify the appropriate T score. So for the degree of freedom and minus one equals 14 and critical values um providing probability 140.99 for the confidence interval,  to identify T C equals 2.977 Now, with this T. C, we can identify the margin of error E, which is given by this formula plugging in our T C. S and N. We obtain E equals 0.572 And now plugging into our confidence interval formula, which is that new falls between a sample mean minus C, and sampling plus E gives us our confidence interval. That new is between 1.781 and 2.9 to 5 with 99% confidence.

A camera is on sale for $130. After a 7.875% sales tax is added, what is the total cost of the camera?​

Answers

$140.2375, $140.24(rounded to hundredth)

$112,500 is the price of 75 towels, how much does 1 cost?

Answers

Answer:

1500

Step-by-step explanation:

112500/75=answer

answer=1500

Answer: 1 towel cost 1,500

Step-by-step explanation: When you divide $112,500 by 75 you get 1,500.

what is the HCF of 2x and x​

Answers

HCF (2x, x) = x.

Factors of 2x = 2 × x × 1

Factors of x = x × 1

Common factors = x, 1

HCF = x × 1 = x

See the attachment too.

________

Hope it helps ⚜

Help please write and solve the equation in the comments

Answers

Answer:

x=34

Step-by-step explanation:

2x-5=3(1/2x+4)

2x-5=3/2x+12

1/2x-5=12

1/2x=17

x=34

Answer:

x=34

Step-by-step explanation:

The price of gas goes up to $3.24 per gallon after a 9.4% increase. What was the price before the increase?

Answers

Answer:

i think this correct

Step-by-step explanation:

3.24=(1+9.4/100) x

then x= 2.961 $

I’m confused on this question

Answers

Answer:

[tex]\lim_{x \to 5}f(x)=-5\\\lim_{x \to 1^-} f(x)=3\\\lim_{x \to 1^+} f(x)=3\\\lim_{x \to 1} f(x)=4\\[/tex]

Step-by-step explanation:

[tex]\lim_{x \to 5}f(x)[/tex]

This means "the limit of f(x) as x approaches 5"

In this case, f(x) is a basic linear function while x > 1, so a limit is not necessary but it can still be used as it is here. For this one, you can just calculate f(5), and that is:

[tex]f(x)=5-2x[/tex]

[tex]f(5)=5-2(5)=5-10=-5[/tex]

[tex]\lim_{x \to 5}f(x)=-5[/tex]

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

[tex]\lim_{x \to 1^-} f(x)[/tex]

This one is a little different. It means "the limit of f(x) as x approaches 1 from the negative (left) direction"

The negative direction of course means x will be less than 1, so we'll use this function:

[tex]f(x)=4-x[/tex]

It's easier if you graph it, but you can also do it like this:

[tex]f(0)=4+0=4\\f(0.5)=4-0.5=3.5\\f(0.75)=4-0.75=3.25\\f(0.9)=4-0.9=3.1\\f(0.99)=4-0.99=3.01[/tex]

There's a clear pattern there. You can see that f(1) should be 3, but this function only applies while x is less than 1 so it can never reach 3. It will get infinitely close, and that can be shown with the limit:

[tex]\lim_{x \to 1^-} f(x)=3[/tex]

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

[tex]\lim_{x \to 1^+} f(x)[/tex]

This one works the same way, but from the positive (right) direction.

[tex]f(2)=5-4=1\\f(1.5)=5-3=2\\f(1.25)=5-2.5=2.5\\f(1.1)=5-2.2=2.8\\f(1.01)=5-2.02=2.98\\f(1.001)=5-2.002=2.998[/tex]

It will also get infinitely close to 3 when x = 1, but won't ever reach it because this function only applies when x is greater than 1.

[tex]\lim_{x \to 1^+} f(x)=3[/tex]

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

[tex]\lim_{x \to 1} f(x)[/tex]

Here, the function for x=1 is just:

[tex]f(x)=4[/tex]

It's given already, so the limit is just:

[tex]\lim_{x \to 1} f(x)=4[/tex]

i need help on this math problem

Answers

Answer:

I cant Really type the thing out, i posted a screen shot

Step-by-step explanation:

please help :( ill give 40 points

Answers

Answer:

1. distance and time are the variables. 2. the variables are related by the speed of the car

Find the length of the hypotenuse, side c, of a right triangle with legs of length a = 4 and b = 5. Use a calculator to estimate the
square root to one decimal place.

Answers

answer:

6.4

Step-by-step explanation:

4^2+5^2=c^2

16+25

square root of 41

c^2=6.4

Each day of Spirit Week at Alek's school, students have the option of dressing up according to a different theme. On Tuesday of Spirit Week, Alek recorded the number of students at his school by class and style of dress. Here is his data:

Answers

Answer:

D

Step-by-step explanation:

or

This is the conditional distribution of style of dress for freshmen.

Please help and give real answers it would be much appreciated

Answers

Answer:

x = 8, x = 10

Step-by-step explanation:

[tex]\sqrt{4x - 31}[/tex] = x - 7 ( square both sides )

4x - 31 = (x - 7)² ← expand using FOIL

4x - 31 = x² - 14x + 49 ( sub 4x - 31 from both sides )

0 = x² - 18x + 80 ← in standard form

0 = (x - 8)(x - 10) ← in factored form

Equate each factor to zero and solve for x

x - 8 = 0 ⇒ x = 8

x - 10 = 0 ⇒ x = 10

As a check

Substitute these values into the equation and if both sides are equal then they are the solutions.

x = 8

left side = [tex]\sqrt{4(8)-31 }[/tex] = [tex]\sqrt{32-31}[/tex] = [tex]\sqrt{1}[/tex] = 1

right side = 8 - 7 = 1

Then x = 8 is a solution

x = 10

left side = [tex]\sqrt{4(10)-31}[/tex] = [tex]\sqrt{40-31}[/tex] = [tex]\sqrt{9}[/tex] = 3

right side = 10 - 7 = 3

Then x = 10 is a solution

show how to find slope of a line that passes through the points in the table​

Answers

Answer:

Step-by-step explanation:

here you go m = (y2-y1)/(x2-x1)

  = (11-(-9))/(3-(-1))

  = 20/4

  = 5

Below are the graphs of the functions y=2x and y3x What is the same about both lines?​

Answers

C they rise upward toward the right

So um anyone know how to do this?

Answers

We need to find distance they travel as a function of time. This simply means that x is the function of time. The destination is 120 miles away, this is irrelevant for the question that is currently being asked. However, we know that they have already travelled 20 miles and are going 50 miles and hour. So lets plug in what we have.

50 is our rate of change, so we match that with the x.

20 is our constant, the distance already travelled.

This means our function is:

f(x) = 50x + 20

This means our answer is D) f(x) = 50x + 20

Lets also plug in 120 to solve how much further they need to travel before arriving.

120 is our f(x) as it is the final distance travelled.

120 = 50x + 20

120-20 = 50x

100 = 50x

100/50 = x

2 = x

This means that they need to travel 2 hours in addition to the 20 miles they have already gone.

I hope I've helped! :)

What is 50% of 35 like simplified

Answers

Answer:

It can't get more simple than that (*nose growing*)

Step-by-step explanation:

50% of 35 means 35 is 100% right? 50 is half of 100. So 50% of 35 will be half of 35, agree? So you multiply by crossing

35 = 100%

x = 50%

100 * x = 35 * 50 (do this math, you can multiply 35 by 5 then add 0)

100x = 1750

x = 1750 / 100

x = 17,5

Is 17,5 half of 35? You could have also done 35 / 2. It would be the same result because 50% is an easy percentage to work with.

A bear cub weighs 10 pounds at birth, and it gains an average of 5 pounds every month.

Answers

Answer:

Just keep adding 5 for each month.

Step-by-step explanation:

10 + 5 = 15

15 is first month

20 second

25 third

30 fourth

35 fifth

40 six

etc.

Equation :

10 + (5m)

m = number of months that have passed by.

kyle took at total of 8 quizzes in the first 4 weeks of school. How many weeks of school will he have to attend before he will have taken a total of 12 quizzes?

Answers

Answer:

6 weeks

Step-by-step explanation:

8 quizzes = 4 weeks

So 2 quizzes/week

It will take her 12/2 weeks (6) to finish 12 quizzes

-Chetan K

someone please help me on this anyone pls no link :(​

Answers

9514 1404 393

Answer:

  The correct answer is marked. (8·3)

Step-by-step explanation:

The order of operations requires that you start with by evaluating expressions in parentheses. Within parentheses, the order of operations applies, so you need to do multiplication before addition.

In this expression, the multiplication operation inside the parentheses is performed first. That is, you first compute 8·3.

_____

Additional comment

After that, you do the subtraction, to get ...

  11 ÷ (-12) +2⁴

Then the exponential term is evaluated, and you have ...

  11 ÷ (-12) +16

The division will result in a fraction, making it ...

  (-11/12) +16

And, finally, the addition gives you ...

  15 1/12

HEY IF YOURE SEEING THIS IM IN DIRE NEED OF YOU SOLVING NUMBER 4!!

Answers

Answer:

(1, -3) (2, -1) (3, 1)

Step-by-step explanation:

if seconds=x and degrees celsius=y, the points are (1, -3) (2, -1) (3, 1). to graph, plot the points on a graph. (ordered pairs are written as x,y)

can some one help me solve this​

Answers

Answer:

time = 0.4, height = 24.8m

Step-by-step explanation:

We need to find the coordinates of the vertex of the parabola.

[tex]f(x)=ax^2+bx+c\\\\v(p,\ q)-\text{vertex}\\\\p=\dfrac{-b}{2a};\ q=f(p)[/tex]

We have

[tex]h(t)=24+4t-5t^2=-5t^2+4t+24\\\\a=-5,\ b=4;\ c=24\\\\p=\dfrac{-4}{2(-5)}=\dfrac{-2}{-5}=\dfrac{2}{5}=0.4\\\\q=h(0.4)=-5(0.4)^2+4(0.4)+24=-5(0.16)+1.6+24\\\\=-0.8+25.6=24.8[/tex]

Can someone help me with this question? please

Answers

It is a quadratic equation. (X-8)(x+8)

For each of the solutions of the equations find two consecutive integers between which the solution is located: x^2=3, x^2=5

Answers

The two consecutive integers between which the solution is located are 1 and 2

The two consecutive integers between which the solution is located are 2 and 3

Given the expressions x^2 = 3 and x^2 = 5

For the equation

x^2 = 3

Take the square root of both sides

x = ±√3

x = 1.732

Hence the two consecutive integers between which the solution is located are 1 and 2

For the expression

x^2 = 5

x = ±√5

x= 2.24

The two consecutive integers between which the solution is located are 2 and 3

learn more on roots here:https://brainly.com/question/12501796

Answer:

1. 1,2       2. 2,3

Step-by-step explanation:

if h(x)=5x+2 and g(x) =9x-4 find (h o g) (3)

Answers

Answer:

h(g(x)) = 45x -18

Step-by-step explanation:

h(g(x)) = 5(9x - 4) + 2

= 45x - 20 + 2

= 45x -18

[tex]\text{Given that,}\\\\h(x) = 5x+2 \\\\g(x) = 9x-4\\\\g(3) = 9(3) -4 =27 -4=23\\\\(h \circ g)(3) \\\\=h(g(3))\\\\=h(23)\\\\=5(23) +2 \\\\=117[/tex]

ratio 12:30 in the form 1:n

Answers

Answer:
1:2.5

Step by step explanation:
12:30
÷ by 12 each side
= 1:2.5

Hope this helps!

elijan un lugar de su escuela o de su localidad y elaboren un croquis a escala muestren su trabajo a la clase e indiquen que escala utilizaron

Answers

Answer:

pls ask the question in english pls i don't understand it

Frame a linear equation for each of the following statements.
1. [tex]b[/tex]47 is 23 more than two times p.
2.[tex]b[/tex]One-fourth of p decreased by 3 gives −12
3.[tex]b[/tex]2 times p exceeds 15 by 3.
4. [tex]b[/tex]One-fifth of p decreased by 4 gives 6

Answers

Answer: chopstick

Step-by-step explanatio

Please answer. Geometry problem. Unit: Degrees

Answers

Answer:

17

Step-by-step explanation:

∠C is common in both triangles

equate them

∠C = 180- (x + 100) = 180 - ( 4x + 49)

x + 100 = 4x + 49

100 - 49 = 3x

51 = 3x

x = 51/3 = 17

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