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18 votes
Solve using elimination. -6x - y = 13 9x – 4y = 19(_,_)

User JuniKim
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1 Answer

18 votes
18 votes

Solving by elimination method.

We have the following system of equations:


\begin{gathered} -6x-y=13 \\ 9x-4y=19 \end{gathered}

we can multiply the first equation by -4, then we have the equivalent system:


\begin{gathered} 24x+4y=-52 \\ 9x-4y=19 \end{gathered}

If we add both equations, we obtain


\begin{gathered} 24x+9x=-52+19 \\ 33x=-33 \\ x=(-33)/(33) \\ x=-1 \end{gathered}

now, we can substitute this values into the first original equation, It yields


\begin{gathered} -6(-1)-y=13 \\ \end{gathered}

then, we have


\begin{gathered} 6-y=13 \\ -y=13-6 \\ -y=7 \\ y=-7 \end{gathered}

Therefore, the answer is x= -1 and y= -7, which correspond to the point (-1,-7).

User Maxsteel
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