02-14-2008
a little late but here you go:
y = -x + 4
-5x + 2y = -6
Substitution method means what it says. They give you what y is (-x+4) so you just substitute it in the lower equation.
-5x + 2(-x+4) = -6
Distribute.
-5x -2x + 8 = -6
Solve for x.
-7x = -14
x = 2
So plug x=2 into the easier equation (either one works)
y = -(2) + 4
y = 2
Answer: (2,2)
Plug them in each equation to check. |