Question

I WILL GIVE BRAINLIST AND 5 STARS Show that (2x + i)(2x – i) = 4x² + 1

Answer 1

Answer:

see below

Step-by-step explanation:

(2x + i)(2x – i)

FOIL

first  2x*2x =4x^2

outer  -i * 2x = 2x i

inner i * 2x = 2x i

last i * -i = -i^2  and i^2 = -1  so - (i^2 ) = - (-1) = 1

Add together

4x^2 + 2xi -2x i +1

Combine like terms

4x^2 +1