Question

Solve the system by substitution.

y=-x
y=4x+45
Multiple Choice.
A.(-9,-9)
B.(9,-9)
C.(9.9)
D.(-9,9)

Answer 1

D x= -9
Y=9
Because 4(-9)+45=9
I just put in each one and d got it right.

Answer 2

y = -x
y = 4x + 45

-x = 4x + 45
- 4x - 4x
-5x = 45
-5 -5
x = -9
y = 4x + 45
y = 4(-9) + 45
y = -36 + 45
y = 9
(x, y) = (-9, 9)

It is equal to B.