5: Any number (besides zero) to the power of zero is 1.

9: The negative exponent can be made positive by moving it to the denominator, leaving a 1 in the numerator.

15: Only the factor with the negative exponent will move to the denominator.

20: Each factor has a negative exponent, so each factor will move in order to make its exponent positive.

26: Add the exponents.

28: You can multiply the exponents before changing the negative.

31: x means x1

32: Add exponents to multiply, and subtract them to divide.

38: You can start by putting (4x) in the denominator with a positive exponent.

39: The numerator and denominator each have a negative exponent, so they both move (that is, the whole fraction gets flipped).

40: Negative times negative is positive.

53: Divide the decimals normally, and divide the powers by subtracting exponents.

72: Take the square root of the numerator and the square root of the denominator.