kakak tolong pakai cara makasih yg dibulatin aja yg dikerjain pakai caranya.

a). 3x + 2x = 180 - 90
5x = 90
x = 90÷5
x = 18

b). # 5x + x = 180-90
6x = 90
x = 90 ÷ 6
x = 15

# 2x + y = 90
2(15) + y = 90
30 + y = 90
y = 90-30
y = 60

d). 2y + y = 90
3y = 90
y = 90÷3
y = 30

x + 40 = 90
x = 90-40
x = 50

e). x + 127 = 180
x = 180 - 127
x = 53

x + y = 90
53 + y = 90
y = 90 - 53
y = 37

f). 4x + 5x = 90
9x = 90
x = 90÷9
x = 10

y = 180 - 4x
y = 180 - 4 (10)
y = 180 - 40
y = 140