Step-by-step explanation:
[tex]4x+(y+x)=180\\\\\text{Solve for}\ x:\\\\4x+y+x=180\qquad\text{combine like terms}\\\\(4x+x)+y=180\qquad\text{subtract}\ y\ \text{from both sides}\\\\5x=180-y\qquad\text{divide both sides by 5}\\\\\dfrac{5x}{5}=\dfrac{180-y}{5}\\\\\boxed{x=\dfrac{180-y}{5}}\\\\\text{Solve for}\ y:\\\\5x+y=180\qquad\text{subtract}\ 5x\ \text{from both sides}\\\\\boxed{y=180-5x}[/tex]
