Minta bantuan. Yg bisa no 4. Tolog bagi ilmunya.

4) a – 4 = 3a
a – 3a = 4
-2a = 4
a = -2

2d – 3 = 11
2d = 11 + 3
d = 14 : 2 = 7

2c = 3c + 8
2c – 3c = 8
– c = 8
c = -8

b = 2b – 5
b – 2b = – 5
-b = -5
b = 5