Problem: y=-8/5x-9 y=-2/5x-3
y=-8/5x-9 y=-2/5x-3
1) y = -8/5 x - 9
2) y = -2/5 x - 3
Substitute the value for y from eqation 2 into
equation 1.
y = -8/5 x - 9
-2/5 x - 3 = -8/5 x - 9
-2/5 x - 3 + 8/5 x = -8/5 x - 9 + 8/5 x
6/5 x - 3 = -9
6/5 x - 3 + 3 = -9 + 3
6/5 x = -6
(6/5 x)(5/6) = -6(5/6)
x = -5
Now, solve for y, using equation 1.
y = -8/5 x - 9
y = -8/5 (-5) - 9
y = 8 - 9
y = -1
Use equation 2 to check the answer.
y = -2/5 x - 3
-1 = -2/5 (-5) - 3
-1 = 2 - 3
-1 = -1
Answer: x = -5, y = -1