Question

Three times the square of non -zero number is equal to nine times the number.

Answer 1

Three times the square of a number means $3x^2$

Nine times a number is $9x$

If these quantities must be equal, we have

$3x^2=9x$

We can divide both sides by 3 to get

$x^2=3x$

Since x is non-zero, we can divide both sides by x:

$x=3$