Answer:
X=5
Y=6
Step-by-step explanation:
9x-7y=3
x-7y=-37 |(-1)
-x+7y=37 +
________
8x=40
x-7y=-37
5-7y=-37
-7y=-42 |(-1)
7y=42
y=6
D
x(-3x+4)=x*(-3)+x*4=-3x^2+4x
z=12
z+15=27
move constant
z=27-15