If you were to use the substitution method to solve the following system, choose the new equation after the expression equivalent to y from the first equation is substituted into the second equation.

8x - y = -9
4x - 3y = -22

Question

If you were to use the substitution method to solve the following system, choose the new equation after the expression equivalent to y from the first equation is substituted into the second equation. 

8x - y = -9 
4x - 3y = -22

***[isuru]*** · Answer

now consider the first equation
                  8x - y = -9
make y the subject
                   y = 8x +9

now plug this value in the second equation u got
                 4x - 3y = -22
                4x - 3( 8x + 9) = -22
now simplify this.. it will give u the new equation the question asks..

can u do that :) ?

lukebluefive · Answer

Following the instructions from the problem, take the first equation and get "y" on a side by itself:
$$8x - y = -9$$
Add y to both sides:
$$8x = y - 9$$
Add 9 to both sides:
$$8x + 9 = y$$
Rotate the equation:
$$y = 8x + 9$$
Then do what Isuru says.