Kay solves the following system of equations using the substitution method. y=−4x+2
3x−y=9

What is the single-variable equation she solves after substituting?

3x−(−4x+2)=9

3x−4x+2=9

3x+9=−4x+2

3x+9=−(4x+2)
PLZ HELP ME SOON

The single-variable equation she solves after substituting is 3x−(−4x+2)=9

They are expressions separated by an equal sign.

Given the system of equations:

To get the required single-variable equation, we will substitute equation 1 into 2 to have:

3x - y = 9

3x - (-4x + 2) = 9

Expand

3x + 4x - 2 = 9

7x = 9 + 2

7x - 11 = 0

Hence the single-variable equation she solves after substituting is 3x−(−4x+2)=9

Learn more on single-variable equation here: link

Step-by-step explanation:

m = (y2-y1)/(x2-x1)

m=  (26-14)/(21-19)

m = 2/3