m<GJI=(x+60)°=?
We need to find x. The angle GJI and FJH are opposite by the the vertex, then they must be congruents:
(x+60)°=(5x)°
x+60=5x
Solving for x
x+60-x=5x-x
60=4x
60/4=4x/4
15=x
x=15
Replacing x by 15 in m<GJI:
m<GJI=(x+60)°=(15+60)°→m<GJI=75°
Answer: Option b. 75