## Precalculus (6th Edition) Blitzer

$x=55^{\circ}$ and $y=35^{\circ}$.
Step 1. Using the right triangle given in the exercise, we have $x+y=90$ or $x=90-y$ degrees. Step 2. A straight line has an angle of $180^{\circ}$; we have $x+(3y+20)=180$ or $x+3y=160$ Step 3. Using substitution, we have $(90-y)+3y=160$, or $2y=70$ and $y=35$ degrees. Step 4. We can conclude that $x=55^{\circ}$ and $y=35^{\circ}$.