Let x and y represent the measure of the unknown angles
x+y=145
x-y= 15
2x=160 (Use the elimination. method)
2/2x=160/2
x=80
80° is the measure of one of the unknown angles
x+y=145
80+y=145
-80 -80
y=65
The measure of the second unknown angle is 65°
Thus the measure of the unknown angles are 80° and 65°
