Vậy
Làm chi tiêt hơn ạ.
(5x - 39 ) . 7 + 3 = 80
( 5x - 39 ) .7 = 80 - 3
( 5x - 39 ) . 7 = 77
5x - 39 = 77:7
5x - 39 = 11
5x = 39 + 11
5x = 50
x = 50 : 5
x = 10
Vậy x = 10
kb với mình đi nguyen huyen trang
(5x - 39).7+ 3 = 80
(5x - 39).7 = 80 - 3
(5x - 39).7 = 77
(5x - 39) = 77 : 7
(5x - 39) = 11
5x = 11 + 39
5x = 50
x = 50 : 5
x = 10
Vậy x = 10