plisss tolongin yaa yang baik hati.. pake cara yaa

gambar 1.

a. 3a + 20 + a = 180
4a = 180 - 20
4a = 160
a= 160 / 4
a= 40

b. 40 + 85 + × = 180
× = 180 - 40 - 85
× = 55

b = 40 + 55 + b = 180
b = 180 - 55- 40
b = 85

jadi a = 40 , b= 85