Factor 4x²+9
I forgot how to do this, want someone to show me.

Question

Factor   4x²+9
 I forgot how to do this, want someone to show me.

thesmartone · Answer

$\Large a^2 + b^2 =(a - bi)(a+bi)$

where i is the imaginary root, i = sqrt(-1)

jocelm · Answer

Oh wow, okay and is that like a formula you just used that can be used for other equations?

thesmartone · Answer

There are a couple other formulas, mhmm

$\Large a^2 - b^2 = (a+b)(a-b)$
$\Large a^2 + 2ab + b^2 = (a+b)^2$
$\Large a^2 - 2ab + b^2 - (a-b)^2$
$\Large a^3 - b^3 = (a - b)(a^2+ab+b^2)$
$\Large a^3 + b^3 = (a+b)(a^2-ab+b^2)$

jocelm · Answer

Thanks so much I couldn't remember!

thesmartone · Answer

Eventually with practice, you should be able to memorize these formulas. They'll help you solve questions much faster (: