+0

# I need an easier way

+1
28
7
+350

So I know how to simplify something like

$$(x+7)(x-7)=x^2-49$$

but can someone give me an easy way to simplify something like

$$(2x-3i)(2x+3i)(x+8)(x+2)=?$$

and I'm also going to ask another question about that math problem when I get this answer, so be warned.

Oh! If anyone needs a tip on LaTeX use, message me.

Sort:

#1
+91229
+3

$$(2x-3i)(2x+3i)(x+8)(x+2)\\ =(4x^2-9i^2)(x+8)(x+2)\\ =(4x^2+9)(x+8)(x+2)\\ =(4x^2+9)(x^2+10x+16)\\ =4x^2(x^2+10x+16)\quad +\quad 9(x^2+10x+16)\\ etc$$

Melody  Dec 1, 2017
#2
+350
+2

I'm sorry, but I need a full polynomial form, not factored form.

#3
+91229
+2

Just expand it our and then collect like terms.  I thought you cold do that yourself :/

Melody  Dec 1, 2017
#4
+350
+3

idk how with polynomials...

#5
+350
+2

and im kinda full with a lot of math at once

#6
+91229
+3

$$=4x^2(x^2+10x+16)\quad +\quad 9(x^2+10x+16)\\ =4x^4+40x^3+64x^2\quad +\quad 9x^2+90x+144\\ =4x^4+40x^3+73x^2+90x+144\\$$

Melody  Dec 1, 2017
#7
+350
+3

thanks

### 25 Online Users

We use cookies to personalise content and ads, to provide social media features and to analyse our traffic. We also share information about your use of our site with our social media, advertising and analytics partners.  See details