Why do people keep saying that -9 squared (no parentheses) equals to -81? I was taught that ANY number squared would be positive.
Notice the difference :
(-9)^2 = (-9) * (-9) = 81
BUT.....
-9^2 actually means -1*9^2 = -1 * 9 * 9 = -81
Moral of the story......parentheses matter !!!!!
