Question

Solve the following​

Answer 1

let’s say the unknown number is x.
therefore,
(2x)^2/3 - 30= 18
4x^2/3 -30 = 18
4x^2-90/ 3 = 18
multiply 18 by 3, and 4x^2-90 by 1
hence,
4x^2-90 = 54
4x^2=144
x^2= 144/4
x^2= 36
x=+ or - 6
hope it helps:)