Answer: x=-4
Step-by-step explanation:
Given
x=-4y
y=2x+9
Rephrase equation to find y value in terms of x
y=-x/4
y=2x+9
Use substitution (substitute value of y)
2x+9=-x/4
Multiply -4 on both sides
-4(2x+9)=-4(-x/4)
-8x-36=x
Add 8x on both sides
-8x-36+8x=x+8x
-36=9x
Divide 9 on both sides
-36/9=9x/9
x=-4
Hope this helps!! :)
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