tolong bantu ya pake cara

180 = a+b+c
a. 180 = 60+70+c
180 = 130+c
180-130 = c
50 = c
b. 180 = 55+80+c
180 = 135+c
180-135 = c
45 = c
c. 180 = 30+110+c
180= 140+c
180-140=c
40=c
maaf kalo salah