\(2(x-51)=2\cdot2^3+20\)
\(2(x-51)=2\cdot8+20\)
\(2(x-51)=16+20\)
\(2(x-51)=36\)
\(x-51=36:2\)
\(x-51=18\)
\(x=18+51\)
\(x=69\)
2 ( x - 51 ) = 2 . 23 + 20
2 ( x - 51 ) = 24 + 20
2 ( x - 51 ) = 16 + 20
2 ( x - 51 ) = 36
( x - 51 ) = 36 : 2
( x - 51 ) = 18
x = 18 + 51
x = 69
Vậy x = 69
Tk nhé!!!