jawab no 6.Plis jawab semoga yg jawab dosanya hilang semua sama tuhan.

80 + 2y = 180
2y = 180 - 80
2y = 100
y = 100/2
y = 50

180 = 2y + 4z + 40
180 = (2 . 50) + 4z + 40
180 = 100 + 4z + 40
180 = 140 + 4z
180 - 140 = 4z
40 = 4z
z = 40/4
z = 10

180 = 40 + 7x
180 - 40 = 7x
140 = 7x
x = 140/7
x = 20

x + y + z
= 20 + 50 + 10
= 80

tapi kok ngak ada jawabannya ya?