## exponets messing me up

This is probably a very easy question but it is messing me up.

(-y^2)^2 = (-y)^4

but

(-y^2)^3 = (-y^6)

why does one exponent need to be inside the brackets and the other outside?

Example: (-5^2)^2 = 625 = (-5)^4

(-5^2)^3 = -15625 = (-5^6)

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 Mentor You really need to move your parentheses to avoid amibiguity; your first line should really read -(y2)2=-(y4)

 Quote by cristo You really need to move your parentheses to avoid amibiguity; your first line should really read -(y2)2=-(y4)
but that would make the answer -625, not 625

Mentor

## exponets messing me up

Sorry, I read it wrong. Well, in that case, you need more parentheses, since -x^2 is very ambiguous; I would take it to mean -(x^2). You should write ((-y)^2)^2, which is equal to (-y)^4, using the correct exponent rule.

 Ok, so ((-y)^2)^3 = (-y)^6
 Mentor Yes. Notice that it is also equal to y^6 if you square the inside bracket first, since (-y)^2=y^2
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