Question

Which of the following expressions is equal to 2x^(2)+8?

(2x-4i)(x-2i)
(2x-4i)(x-2i)
(2x+4i)(x+2i)
(2x_2i)(x+6i)

Answer 1

Answer: (2x-4i)(x+2i)

Explanation:

Answer 2

The expression equal to 2x^(2)+8 is:

First option (2x-4i)(x+2i)

Explanation:

If we multiply

(2x-4i)(x+2i)=(2x)(x)+(2x)(2i)-(4i)(x)-4i(2i)

(2x-4i)(x+2i)=2x^(1+1)+4xi-4xi-8i^(1+1)

Simplifying:

(2x-4i)(x+2i)=2x^2-8i^2

and i^2=-1, then:

(2x-4i)(x+2i)=2x^2-8(-1)

Multiplying:

(2x-4i)(x+2i)=2x^2+8