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44 votes
44 votes
X - 9y = 20 -8x + 18y = 2

User Alex Che
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1 Answer

24 votes
24 votes

The given system is


\begin{cases}x-9y=20 \\ -8x+18y=2\end{cases}

First, we multiply the first equation by 8


\begin{cases}8x-72y=160 \\ -8x+18y=2\end{cases}

Then, we combine the equations


\begin{gathered} 8x-8x-72y+18y=160+2 \\ -54y=162 \\ y=(162)/(-54) \\ y=-3 \end{gathered}

Now, we find x


\begin{gathered} x-9y=20 \\ x-9(-3)=20 \\ x+27=20 \\ x=20-27 \\ x=-7 \end{gathered}

Hence, the solution to the system is (-7, -3).

User AngryParticle
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