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Solve the system using substitution x=-4y y=2x+9

User Unhammer
by
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1 Answer

10 votes
10 votes

Answer: x=-4

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!! :)

Please let me know if you have any questions

User Offwhitelotus
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