\(Question \ 1) \ x + 3y = 9\)
\(x=9-3y\) \(|Subtract \ 3y \ from \ both \ sides|\)
\(Question \ 2) \ 3x - 3y = -13\)
\(3(x-y)=-13\) \(|Factor \ out \ the \ common \ term \ 3|\)
\(x-y= \dfrac{13}{3}\) \(|Divide \ both \ sides \ by \ 3|\)
\(x=- \dfrac{13}{3}+y\) \(|Add \ y \ to \ both \ sides|\)
\(x=y- \dfrac{13}{3}\) \(|Regroup \ terms|\)
