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

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

set each factor equal to 0

4x-3 = 0

2x-1 = 0

solve for x.

4x-3=0

4x=3

x= 3/4

solve for x. 

2x-1= 0

2x= 1

x= 1/2

your answer should be 1/2 is less than or equal to x and 3/4 is greater than or equal to x