jean

A system of equations is shown below. y = 4x y = x – 6 What is the x­ value in the solution to the system?

$\begin{array}{rcll} (1) & y &=& 4x \\ (2) & y &=& x - 6 \\ \hline \\ (1) = (2) & y &=& 4x = x - 6 \\ & 4x &=& x - 6 \qquad & |\qquad -x \\ & 4x-x &=& - 6 \\ & 3x &=& - 6 \qquad & |\qquad :3 \\ & x &=& \frac{- 6}{3} \\ & \mathbf{ x }&\mathbf{=}& \mathbf{-2} \\\\ & y &=& 4x \\ & y &=& 4\cdot(-2) \\ & \mathbf{y} &\mathbf{=}& \mathbf{-8} \end{array}$