( 7x - 11)3 = 1000
=> (7x - 11)^3 = 10^3
=> 7x - 11 = 10
7x = 21
x = 3
(7.x - 11)3 = 25 . 52 + 200
(7.x - 11)3 = 1000
(7.x - 11)3 = 103
=> 7.x - 11 = 10
=> 7.x = 10 + 11
=> 7.x = 21
=> x = 21 : 7 = 3
(7.x - 11)3 = 25 . 52 + 200
=>(7.x - 11)3 = 1000
=>(7.x - 11)3 = 103
=> 7.x - 11 = 10
=> 7.x = 10 + 11=21
=> x = 21 : 7 = 3
vậy x=3
\(\left(7x-11\right)^3=2^5.5^2+200.\)
\(\left(7x-11\right)^3=800+200\)
\(\left(7x-11\right)^3=1000\)
\(\left(7x-11\right)^3=10^3\)
\(7x-11=10\)
\(7x=10+11\)
\(7x=21\)
\(x=21:7\)
\(x=3\)
