Question

Simplify: (2 + i)^3

Answer 1

(2 + i)^3 = (2+i)(2+i)(2+i)

Answer 2

( 2 + i)³ = 8 - 12i - 6 - i
= 2 - 13i

Answer 3

I was just giving a hint

Answer 4

Chlorophyll, if you're going to do that, you should at least show all of the steps

Answer 5

Recall\[(a+b)^3=a^3+3a^2b+3ab^2+b^3\]Let a=2 and b=i\[(2+i)^3=2^3+3(2^2)i+3(2)i^2+i^3=8+12i-6-i=2+11i\]Not quite as above, but I think I'm close.

Answer 6

Good job @AnimalAin . At least what you posted is correct.

Answer 7

@AnimalAin I missed the signs! thanks for showing it :)

Answer 8

Not like I never missed a sign.....

Answer 9

2-13i