Question

Calculează valoarea lui a,120=(3•a+3)•3+3

Answer 1

120=(3a+3)3+3
120-3=9a+9
117-9=9a
a=108:9
a=12

Answer 2

120=(3•a+3)•3+3
(3•a+3)•3 = 120 - 3
(3•a+3)•3=117
3a + 3 = 117:3
3a+3 = 39
3a = 39 - 3
3a = 36
a = 36 : 3
a =12