Question

Solve the system using the addition method.3x+4y=-105x-2y=18What is the x-value in the solutionA. 2B. -2C. -4D. None of the above

Answer 1

First, we multiply the 2nd equation by (2). We have:

$\begin{gathered} 2\times\lbrack5x-2y=18\rbrack \\ 10x-4y=36 \end{gathered}$

Now, we have:

$\begin{gathered} 3x+4y=-10 \\ 10x-4y=36 \end{gathered}$

We add both equations and solve for x. Shown below:

$\begin{gathered} 3x+4y=-10 \\ 10x-4y=36 \\ ----------- \\ 13x=26 \\ x=\frac{26}{13} \\ x=2 \end{gathered}$AnswerA