Y=2x,x+y=9 solve by substitution show work

Answer:

  (b)  x +2y = 8

Step-by-step explanation:

There are at least a couple of ways to come to the conclusion.

  1) use the given information to write the equation of the desired line

  2) check to see which of the answer choices satisfies the requirement

__

The given line has two specified points on it. These can be used to find its slope. (Or, you can count grid square to see it has a rise of -1 for a run of +2.)

The slope formula is ...

  m = (y2 -y1)/(x2 -x1)

  m = (-4 -0)/(4 -(-4)) = -4/8 = -1/2

Comparing this to our grid square count, we see they are the same:

  m = rise/run = -1/2

Now, we have a slope (-1/2) and a point (2, 3), so we can use these to write the point-slope equation of the desired line:

  y -k = m(x -h) . . . . . . . line with slope m through point (h, k)

  y -3 = -1/2(x -2) . . . . . point-slope equation of the desired line

  y -3 = -1/2x +1 . . . . . . eliminate parentheses

  1/2x +y = 4 . . . . . . . . add 1/2x +3 to both sides

  x +2y = 8 . . . . . . . . . multiply by 2

__

Perhaps easier in this case is to try the given equations to see which is satisfied at the given point. There are two different left-side expressions to evaluate at the point (x, y) = (2, 3):

  x +2y = (2 +2(3)) = 2+6 = 8

  2x +y = 2(2) +3 = 4 +3 = 7

Only the equation ...

  x +2y = 8

is satisfied at the given point.

_____

Additional comments

While I encourage you to learn to solve questions like this "from scratch", modern math curriculum is often "multiple choice."

When faced with multiple choices for answers, it is often easiest to ...

  (a) eliminate the ones that are not self-consistent or that are false on their face;

  (b) eliminate the ones that have an obviously fatal flaw (wrong sign of slope, too large or too small, for example);

  (c) choose from the remaining ones the one that properly answers the question (satisfies all requirements).

__

When you solve a standard-form equation for y, you get ...

  ax +by = c

  by = -ax +c

  y = -a/bx +c/b

That is, the slope of the line is -a/b.

For the two left-side expressions in the answer choices, the slopes are ...

  x +2y   ⇒   slope = -1/2

  2x +y   ⇒   slope = -2/1 = -2

The scales on the graph are the same in the x- and y-directions, so the shallow negative slope of the given line is clearly less than 1. That eliminates the last two answer choices already.

ans=3x+1

Step by step solution

=3(x+2)-5

=3x+6-5

=3x+1

Answer: False

Step-by-step explanation:

Answer:

Just right

Step-by-step explanation:

BRAIN PLS

Answer:

supplementary angles - two angles are supplementary when they add up to 180 degrees (a straight line)

complementary angles - two angles are complementary when they add up to 90 degrees (a right angle)

hopefully this helps! :)

Answer:

1. complementary

2. neither

3. supplementary

4. complementary (x = 6)

10x + 30 = 90         x + 3 = 9          x = 6

5. supplementary (x = 20)

4x + 40 + 3x = 180       7x = 140       x = 20

6. x = 50.5

2x + 79 = 180     2x = 101       x = 50.5

Step-by-step explanation:

When the measurement of the angles adds up to 90 degrees, the angles are complementary. When the sum of the angles is 180 degrees, then they are supplementary.

Angles can be used to estimate the side lengths of a shape.

The letters in order of greatest to least are (a), (b) and (c)

The sum of angles at side (a) is:

[tex]a = 30 + 50[/tex]

[tex]a = 80[/tex]

The sum of angles at side (c) is:

[tex]c = 50 + 90[/tex]

[tex]c = 140[/tex]

The sum of angles at side (b) is:

[tex]b = 40 + 90[/tex]

[tex]b = 130[/tex]

So, we have:

[tex]a = 80[/tex]

[tex]b = 130[/tex]

[tex]c = 140[/tex]

The smaller the base angles, the longer the side.

Hence, the letters in order of greatest to least are (a), (b) and (c)

Read more about angles at:

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Answer:

y = - [tex]\frac{5}{4}[/tex] x + 7

Step-by-step explanation:

The equation of a line in slope- intercept form is

y = mx + c ( m is the slope and c the y- intercept )

Calculate m using the slope formula

m = [tex]\frac{y_{2}-y_{1} }{x_{2}-x_{1} }[/tex]

with (x₁, y₁ ) = (0, 7) and (x₂, y₂ ) = (4, 2) ← 2 points on the line

m = [tex]\frac{2-7}{4-0}[/tex] = [tex]\frac{-5}{4}[/tex] = - [tex]\frac{5}{4}[/tex]

The line crosses the y- axis at (0, 7 ) ⇒ c = 7

y = - [tex]\frac{5}{4}[/tex] x + 7 ← equation of line

Answer:

20.

Step-by-step explanation:

Plugging m = 7 and n = 5 into the given expression:

Answer = 4 + (7 - 5)^4

= 4 + 2^4

= 4 + 16

= 20.

Answer:

Option B: [tex]y=\left \{ {{x^2+6,x<3} \atop {-x+6,x\geq3}} \right.[/tex]

Step-by-step explanation:

We can see that the first part of the piecewise function is a parabola with a y-intercept of (0,6) where the domain is restricted for all values of x less than 3 given the open circle at x=3.

The second part of the piecewise function is a linear function with a negative slope where the domain is restricted for all values of x greater than or equal to 3 given the closed circle at x=3.

Essentially, the piecewise function has a jump discontinuity at x=3 where the first part of the function goes to the second part of the function at one point by "jumping".

Answer: By using the rounding rule.

Step-by-step explanation:

387 x 397 => 387.4

384 x 352 => 387.4

Fractions are written as a ratio of two integers. The product of the fractions in its simplest form is 15/77

Fractions are written as a ratio of two integers

Give the expression

10/11 x 3/7 x 1/2

This can also be written as:

10/2 * 1/11 * 3/7

= 5/11 * 3/7

= 15/77

Hence the product of the fractions in its simplest form is 15/77

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Answer:

21

Step-by-step explanation:

30/100 × 70= 2100/100

= 21

Answer:

-3

Step-by-step explanation:

I just need 20 characters to help out so yeah

Answer:

see explanation

Step-by-step explanation:

For a function each value of x in the domain must map to exactly one unique value of y in the range.

This is the case here so it is a function.

The domain is the x- coordinates of the points

domain is { 5, 6, 7 }

The range is the y- coordinates of the points

range is { 2, 3, 4 }

Step-by-step explanation:

get add and add on ok

Answer:

see the attachment

I hope it's help you

Let the two numbers be X and Y

Sum of the two numbers = 5

⇛ X+Y = 5-----(1)

Difference of their squares = 5

⇛ X²-Y² = 5

⇛(X+Y)(X-Y) = 5

⇛5(X-Y) = 5

⇛X-Y = 5/5

⇛ X-Y = 1

The difference of the two numbers = 1. Ans.

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Answer:

[tex]t\leq2[/tex]

Step-by-step explanation:

200 - 44 = 156 dollars which Shane can use to buy tickets

156 >= 78t

t<=2

Therefore the maximum number of tickets he can buy is 2

Answer:

(3x - 5y + 1)(3x + 5y + 1).

Step-by-step explanation:

9x²+6x+1-25y²

= 9x^2 - 25y^2 + 6x + 1

= (3x - 5y)(3x + 5y) + 6x + 1

3x + 3x = 6x and 1 * 1 = 1 so we have:

= (3x - 5y + 1)(3x + 5y + 1)

Answer:10r-54

Step-by-step explanation: you need to distribute following pemdas

Answer:

The personal hygiene part of the store (I think)

Step-by-step explanation:

This is an ultimately weird question, so I don't really know. But my answer is what I think, (I don't even know if it exists though).

Answer:

x + 27

 ——————

 x + 3

Step-by-step explanation:

Answer:

L

Step-by-step explanation:

The required change in the price of the share of stock is $4.4.

Given that,
On September 1, you own 12.5 shares of stock that are worth $149.87. On December 1, the shares are worth $94.87, and the change in the price per share of stock is to be determined.

The process in mathematics to operate and interpret the function to make the function or expression simple or more understandable is called simplifying and the process is called simplification.

Here,
Initial total cost shares of stock = $149.87
A total number of shares = 12.5
The initial cost of single share = 149.87/ 12.5 = $11.98
Now final cost of the total share = $94.87
The final cost of the single share is = 94.87 / 12.5 = $7.58
Change in price of shares of stock = 11.98 - 7.58 = $4.4

Thus, the required change in the price of the share of stock is $4.4.

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Answer:

there is no more number than one

Step-by-step explanation:

1. This is a ratio question in disguise.

By parts of the question: "When y varies directly with x" -> y/x

"if y=8 when x=4" -> y/x = 8/4

"how do you find y when x=5" -> y/x = 8/4 = y/5

so  -y  = 8x5/4 = 10

That's all i got..

Answer:

Step-by-step explanation:

There is no answer I looked it up and it said 0=0