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27 votes
27 votes
Solving systems with subtraction

User Ymz
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1 Answer

12 votes
12 votes

We have the following system of linear equations:


\begin{gathered} y-5=x \\ x=-2-y \end{gathered}

We can take the first equation, and express y in terms of x:


y=x+5

Now we can plugin y in the second equation and solve for x:


\begin{gathered} x=-2-(x+5) \\ x=-2-x-5 \\ x+x=-2-5 \\ 2x=-7 \\ x=-(7)/(2) \end{gathered}

We take the first equation y = x+5, replace x and find y:


\begin{gathered} y=-(7)/(2)+5 \\ y=(3)/(2) \end{gathered}

Answer: (-7/2, 3/2)

User Lomaxx
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