Question

Solve x + 3y = 9. 3x – 3y = –13

Answer 1

$Question \ 1) \ x + 3y = 9$ 

$x=9-3y$  $|Subtract \ 3y \ from \ both \ sides|$ 

$Question \ 2) \ 3x - 3y = -13$ 

$3(x-y)=-13$   $|Factor \ out \ the \ common \ term \ 3|$

$x-y= \dfrac{13}{3}$   $|Divide \ both \ sides \ by \ 3|$

$x=- \dfrac{13}{3}+y$  $|Add \ y \ to \ both \ sides|$

$x=y- \dfrac{13}{3}$  $|Regroup \ terms|$