Question

solve for X & y solve x + 4y = 0 when y = -2x + 7

Answer 1

Substitute -2x+7 for y in the equation x+4y=0 to obtain the value of x.

$\begin{gathered} x+4(-2x+7)=0 \\ x-8x+28=0 \\ 7x=28 \\ x=\frac{28}{7} \\ =4 \end{gathered}$

Substitute 4 for x in the equation y=-2x+7 to btan the value of y.

$\begin{gathered} y=-2\cdot4+7 \\ =-8+7 \\ =-1 \end{gathered}$

So answer is (4,-1).