3x - 2y = 17
substitute x with 3y+15
3(3y+15) - 2y = 17
use the distributive property
9y + 45 - 2y = 17
combine like terms 9y and -2y
7y + 45 = 17
subtract 45 from both sides
7y = -28
divide both sides 7 to isolate the variable, y.
y = -4
To solve for x:
x = 3y + 15
plug in -4 for y
x = 3(-4) + 15
multiply
x = -12 + 15
add
x = 3
