(7x-11)3 = 25.52+ 23.52
(7x-11)3 = 23.52( 22+1)
(7x-11)3 = 23.53=(2.5)3
7x-11=10
x=3
ban anhduc1501 hinh nhu lam chua dung to nghi vay
(7x - 11)3 = 25 . 52 + 200
(7x - 11)3 = 32 . 25 + 200
(7x - 11)3 = 800 + 200
(7x - 11)3 = 1000
(7x - 11)3 = 103
7x - 11 = 10
7x = 21
x = 3