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7 X= 7 - 2y 2x + y = 5

User TongChen
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1 Answer

2 votes

As the given lines are


\begin{gathered} 7x=7-2y \\ 2x+y=5 \end{gathered}

The value of y from equation 2 is:


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

Put this value of y in equation 1:


\begin{gathered} 7x=7-2y \\ 7x=7-2(5-2x) \\ 7x=7-10+4x \\ 7x-4x=7-10 \\ 3x=-3 \\ x=-1 \end{gathered}

Now put this value of x in equation y=5-2x:


\begin{gathered} y=5-2x \\ y=5-2(-1) \\ y=5+2 \\ y=7 \end{gathered}

So the values are

x=-1 and y=7

User Johannes Kuhn
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3.9k points