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17 votes
17 votes
What is the x-value of the solution to this system of equations? 6x + 8y = -18x = -2y - 5

User Peter Remmers
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1 Answer

24 votes
24 votes

Since the second equation is x in function of y, we can use the substitution method to find y and then find x

First, we substitute x from the second equation into the first equation:


\begin{gathered} 6(-2y-5)+8y=-18 \\ -12y-30+8y=-18 \end{gathered}

And solve for y:


\begin{gathered} (-12+8)y-30=-18 \\ -4y=-18+30 \\ -4y=12 \\ y=(12)/(-4)=-3 \end{gathered}

And now we replace y = -3 into the second equation:


\begin{gathered} x=-2y-5 \\ x=-2\cdot(-3)-5 \\ x=6-5 \\ x=1 \end{gathered}

The x-value of the solution is 1

User Javier Fajardo
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3.0k points
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