math problem. i have to multiply the binomials together, (x+2i) times (x2i).
HOW?!
8 Answers

(x+2i)(x2i)
= x(x2i) + 2i(x2i)
= x^2 – 2ix + 2ix 4i^2
= x^2 – 4(1)
= x^2 + 4

F.O.I.L. = First Outer Inner Last
First = x * x = x^2
Outer = x * 2i = 2ix
Inner = 2i * x = 2ix
Last = 2i * 2i = 4i^2 = 4(1) = 4
Add them all up:
x^2 – 2ix + 2ix + 4 = x^2 + 4

in case you distribute from the beginning up, the equation could in basic terms be x+2 • x2 • x+2i • x 2i. So, it fairly is 4 x’s, and in case you upload togeher each and all the +2s and 2s, youd have 0. (+2+2=0. And +2i+2i=0. they cancel eachother out) so which you basically have the 4 x. So the equation simplified is 4x. in basic terms look at each and all the 2s. They cancel eachother out, and your left with basically the x’s.

X 2i

Use the formula
( a + b )( a – b ) = a² – b²
= ( x + 2i )( x – 2i )
= ( x )² – ( 2i )²
= x² – 4i²
= x² + 4
hope this helps
Bye !!

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

(x + 2i)(x – 2i)
= x(x) – x(2i) + 2i(x) – 2i(2i)
= x^2 – 2ix + 2ix – 4i^2
= x^2 – 4(1)
= x^2 – (4)
= x^2 + 4

See my answer to your other question!