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Solve the system with elimination.3x + y = 9x + 2y = 3

Solve the system with elimination.3x + y = 9x + 2y = 3-example-1
User Pltrdy
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1 Answer

27 votes
27 votes

In order to solve by elimination, let's multiply the first equation by -2. This way, when we add the equations, the variable y will be canceled out:


\begin{cases}-6x-2y=-18 \\ x+2y={3}\end{cases}

Now, adding the equations, we have:


\begin{gathered} -6x-2y+x+2y=-18+3\\ \\ -5x=-15\\ \\ x=(-15)/(-5)\\ \\ x=3 \end{gathered}

Now, calculating the value of y, we have:


\begin{gathered} x+2y=3\\ \\ 3+2y=3\\ \\ 2y=0\\ \\ y=0 \end{gathered}

Therefore the solution is (3, 0).

User Dariux
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