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
i think . it is c
10^2x²-3=10^9-x²
by comparison,
2x²-3=9-x²
3x²=12
x²=4
x= 2 or -2
