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

x^2 – 4 = 0 AND 4x^2 = 16

Explanation:

a) x^2 – 4 = 0 --> (x + 2)(x - 2)=0 --> x= -2 AND x= +2

b) x^2 = -4 doesn't have any solution in the real numbers.

c) 3x^2 +12 = 0 -->(divide by 3)--> x^2 +4 =0 ---> x^2 = -4 as b)

d) 4x^2 = 16 -->(divide by 4)--> x^2 = 4 --> x^2 -4 = 0 as a)

e) 2(x -2)^2 =0 -->(divide by 2)--> (x-2)^2 =0 --> one solution that is x=+2