Question

(2.x-1)^4=81

Answer 1

Vì \(3^4=81\)=> 2x-1=3

=> 2x= 3+1

=>2x=4

x=2

Answer 2

A=1+5+5^2+....+5^50

Answer 3

(2x-1)⁴=81=3⁴

=> 2x-1=3

=> 2x   =3+1

=> 2x   =4

=>  x    =4:2

=>  x    =2