Ta có: (2x +1)3 =125
(2x +1)3 = 53
2x + 1 = 5
2x = 4
x = 2
( 2x + 1 ) \(^3\)= 125
( 2x + 1 ) = \(\sqrt[3]{125}\)
( 2x + 1 ) = 5
2x = 5 - 1
2x = 4
x = 4 : 2
x = 2
Ta dễ dàng thấy : 125 = 53
=> \(2x+1=5\)
\(=>2x=4\)
\(=>x=2\)
T thì nói nha
( 2x + 1 ) 3 = 125
( 2x + 1 )3 = 53
2x + 1 = 5
2x = 5 - 1 = 4
x = 4 : 2
x = 2
vậy x = 2
(2x+1)^3=125
(2x+1)^3=5^3
2x+1=5
2x=4
x=2
(2x+1)3=125
(2x+1)3=53
(2x+1)=5
2x=5-1
2x=4
x=4:2
x=2