Negative and Fractional Powers Made Simple
Negative powers aren't scary once you know the secret – they just mean "flip it and make it positive." So 3⁻² = 1/3² = 1/9. Think of the negative sign as instructions to put the number on the bottom of a fraction instead.
Fractional powers are actually roots in disguise. When you see 25^(1/2), the bottom number (2) tells you it's a square root, so the answer is 5. For something like 9^(3/2), you take the square root first (getting 3), then cube it (getting 27).
The trickiest bit is combining negative and fractional powers, like 16^(-3/2). First work out 16^(3/2): take the square root (4), then cube it (64). Because of the negative sign, your final answer is 1/64.
When dealing with fractions like (4/9)^(3/2), apply the power to both the top and bottom separately. Square root of 4 is 2, cubed gives 8. Square root of 9 is 3, cubed gives 27. So your answer is 8/27.
Remember: With negative fractional powers of fractions, work out the positive version first, then flip your final answer!