Substitute 7 for y in y = -x + 4.
7 = -x + 4
Add x to both sides and subtract 7 from both sides.
x = 4 - 7
x = -3.
Substitute 7 for y in y = -x + 4.
7 = -x + 4
Add x to both sides and subtract 7 from both sides.
x = 4 - 7
x = -3.