If you have a fraction raised to a negative power, you can get rid of the negative power using this rule: (x/y)^-n = (y/x)^n. For example, (3/5)^-1=(5/3)^1=5/3. Another example: (x/4)^-2=(4/x)^2=16/x^2. Do you see what happens when we "get rid of" the negative exponent? We flip the fraction. One more example: (3y^2/10)^-3 = (10/(3y^2))^3 = 1000/(27y^6). See how everything that was in the numerator ended up in the denominator and vice versa? A negative exponent makes the fraction "flip." It goes back to this basic definition: x^-1 = 1/x...in words, x to the -1 is the reciprocal of x.
