Question

Which equations are true for x = –2 and x = 2? Select two options

x2 – 4 = 0
x2 = –4
3x2 + 12 = 0
4x2 = 16
2(x – 2)2 = 0

Answer 1

Number 1 and Number 4

Explanation:

By factoring, you can figure out the roots (x = -2 or x = 2)...

1. x^2 - 4 = 0

--> (x + 2)(x - 2) = 0

--> x = -2, x = 2

2. x^2 + 4 = 0

--> factors weirdly, so I won't write it. You'd have to use the quadratic formula.

3. 3x^2 + 12 = 0

--> 3 (x^2 + 4) = 0

--> factors weirdly (same as above)

4. 4x^2 - 16 = 0

--> 4 (x^2 - 4) = 0

--> 4 (x+2) (x-2) = 0

--> x = -2, x = 2

5. 2 (x-2) 2 = 0

--> x = 2