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

1. x² - 4 = 0

4. 4x² = 16

Explanation:

x = –2 and x = 2

1. x² – 4 = 0

+4 +4

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x² = 4

√x² = √4

x = ±2

2. x² = –4

√x² = √-4

x = ±2i

3. 3x² + 12 = 0

3(x + 4) = 0

3 = 0, x + 4 = 0

-4 -4

------------

x = -4

x = 0, -4

4. 4x² = 16

÷4 ÷4

-----------------

x² = 4

√x² = √4

x = ±2

5. 2(x – 2)2 = 0

×2

--------------------

4(x - 2) = 0

÷4 ÷4

------------------

x - 2 = 0

x = 2

Only equations 1 and 4 are true

I hope this helps!