Question

If the two angles below are supplementary, solve for x.

Answer 1

$\bf \stackrel{\textit{supplementary angles add up to }180^o}{(7x)+(5x+24)=180}\implies 12x+24=180\\\\\\12x=156\implies x=\cfrac{156}{12}\implies x=13$

Answer 2

Supplementary angles always equal 180. Then you just solve from there.

7x+5x+24=180
12x+24=180
-24 -24
12x=156
/12 /12
X=12