Question

Complete the table by providing justification for each step of the proof

Conjecture: If 4(x^2-2)=28, then xis 3 or -3

Answer 1

4(x² - 2) = 28

1. Distribute the 4
4x² - 8 = -28

2. Plug in 3 and -3
4(3)² - 8 = 28
4(-3)² - 8 = 28

3. Square 3 and -3
4(9) - 8 = 28
4(9) - 8 = 28

28 = 28

The reason both answers are the same is because whenever you put a negative number to an even power, the result becomes positive because any negative multiplied by a negative number is always positive.
28 = 28