nyatakan persamaan diatas dengan x

Maaf kalau salah, semoga membantu

Bab Aljabar Dasar
Matematika SMP Kelas VII

5] S = (1/3) (x + b) a
x + b = S . (3/a)
x = (3S/a) - b
x = (3S - ab)/a

6] a = (3/2) (x + a)
x + a = (2/3) a
x = (2a/3) - a
x = (2a - 3a)/3
x = -a/3