Question

Complete the table by providing justification for each step of the proof. Conjecture: If 4(x2 – 2) = 28, then x is 3 or –3

Answer 1

4(x2 – 2) = 28
4x^2-8=28 Distributive law of multiplication

4x^2+8=28+8 Additive identity
4x^2=36 ; adding 8 to both sides
x^2 =9, dividing both sides by 4
x= +/- 3