twenty times the square of a non-zero number is equal to 15 times the number. what is the number?

Answer 1

20x^2 = 15x
20x^2 - 15x = 0
5x(4x-3) = 0
so x=0 or x=3/4, but x wan non-zero so

x = 3/4

check:
20(9/16) = 45/4
15(3/4) = 45/4 , yup!