find the mistake

 Examine the following problems. Find the mistake in each. Show that the problems are incorrect by substituting the following values for the variables: a = 3, b = 2, n = 4; or by working both sides of the equation and showing that they are not equal, then rework the problems correctly, explaining your steps and using Equation Editor.  1) ????????3 ∙ ????????4 = ????????12 2) 516 54 = 54 3) (???????? + ????????)2 = ????????2 + ????????2 4) (4????????)3 = 4????????3 5) 32 ∙ 34 = 96 6) ????????−???????? = − 1 ???????????????? 7) (???????? + ????????)−1 = 1 ???????? + 1 ???????? 8) (2????????2)3 = 6????????5