Can someone please explain elaborately why. (-3)^2 is not the same as -3^2
Ok don't be too elaborate. I get the right answer on a calculator but I don't know how to do it by hand.

The brackets keep the - (negative) attached to the three.
So for (-3)^2 it is (-3) x (-3).

When you don't put the bracket the negative gets lost so it becomes -3 x 3

(-3)^2 = (-3)(-3) = 9
but
-3^2 = -(3)^2 = -9