(7x - 15).8 - 21 = 27
(7x - 15).8 = 27 + 21
(7x - 15).8 = 48
7x - 15 = 48:8
7x - 15 = 6
7x = 6 + 15
7x = 21
x = 21 : 7
x = 3
Vậy x = 3
(7x - 15).8 - 21 = 27
(7x - 15).8 = 27 + 21
(7x - 15).8 = 48
7x - 15 = 48:8
7x - 15 = 6
7x = 6 + 15
7x = 21
x = 21 : 7
x = 3
Vậy x = 3