# Thread: (-5^2)^3 = -15625? What?

1. ## (-5^2)^3 = -15625? What?

Just like the subject header says:

(-5^2)^3 = -15625?

My calculator and text seem to agree. Why? Wouldn't the -5^2 in parenthesis process before the ^3? Shouldn't all exponent values outside the parenthesis create a positive number since -5^2 = 25?

PEMDAS says parenthesis then exponents. I'm sure I'm missing something easy here...

Thanks for any help.
Oh and, hi everyone this is my first ever post.

2. But the -5 is not being squared. This is the difference between $(-5)^2$ and $-(5^2)$. Which way should it be if there are no parentheses? Do the exponent before the negative!!

Then, once you know what the -5^2 equals (it is -25 and not 25), you can cube it. The result is negative.

3. ## doh

Doh! Thank you sir.

So, in the expression (-5^2)^3, the exponent on the outside is what dictates sign seeing as -5^2 is always going to be -25. Gotcha.