Answer
$65^{\circ}; 115^{\circ}$
Work Step by Step
1. Supplementary angles have a sum of 180 degrees
$(3x+5) +5x+15) =180$
2. Solve for x :
$8x+20=180$
$8x=160$
$x=20$
3. Replace x to find the angles:
$5(20)+15=115 ^{\circ}$
$3(20)+5=65 ^{\circ}$
