Two angles are supplementary when they <span>add up to 180 degrees </span>⇒
m∠1 + m∠2 = 180°
4y + 7 + 9y + 4 = 180
13y + 11 = 180
13y = 180 - 11
13y = 169
y = 169/13
y = 13
m∠2 = 9y + 4 = 9 * 13 + 4 = 121°
So you multiply 2 1/3times 1 1/2 and you get 3 and 1/6
Each exterior angle is 11.25°
This is the answer...hope i helped
