Tolong jawab ya,pake cara,makasiii

(3x +15)+(2x+15) = 180
5x + 30 = 180
5x = 150
x = 30

COB = 2x + 15 = 2(30) + 15 = 75

3x + 15 + 2x + 15 = 180
5x + 30 = 180
5x = 180-30
5x = 150
× = 150:5
x = 30
Sudut COB
= 2x + 15
= 2.30 + 15
= 60 + 15
= 75