# Problem Inside

• Dec 6th 2007, 05:48 AM
ForgottenMemorie
Problem Inside
Hello People. Im new hence the 1 post.

I have a problem, i recived some questions that i carnt work out, ive read books but cannot get it.

Here are so examples of problems:

Multipy:

A: (3x+3)(9x-2)

2 2
B: (x +3x)(4x -1.5x+2)

(x is squared and 4x is squared)

-1 -0.5 2
C: (x + 6x)(3+x +2x

(x with -1 at the top and 3+x with -0.5 at the top of, 2x squared.)

Can anyone work those out, and show the steps please, much appriciated.
• Dec 6th 2007, 05:53 AM
janvdl
Quote:

Originally Posted by ForgottenMemorie
Hello People. Im new hence the 1 post.

I have a problem, i recived some questions that i carnt work out, ive read books but cannot get it.

Here are so examples of problems:

Multipy:

A: (3x+3)(9x-2)

2 2
B: (x +3x)(4x -1.5x+2)

-1 -0.5 2
C: (x + 6x)(3+x +2x

Can anyone work those out, and show the steps please, much appriciated.

Welcome to the forum! (Handshake) :)

A) $(3x+3)(9x-2)$
$= (3x \times 9x) + (3x \times -2) + (3 \times 9x) + (3 \times -2)$
$= 27x^2 - 6x + 27x - 6$
$= 27x^2 + 21x - 6$

Can you finish the rest now?
• Dec 8th 2007, 03:10 AM
ForgottenMemorie
Last bit = 48x^2 - 6 ?

I'll try the rest using hte same principal. I'll be back if i get stuck.

Thanks for the help.
• Dec 8th 2007, 05:20 AM
janvdl
Quote:

Originally Posted by ForgottenMemorie
Last bit = 48x^2 - 6 ?

I'll try the rest using hte same principal. I'll be back if i get stuck.

Thanks for the help.

No, remember that you can't add variables with different exponents.
• Jan 8th 2008, 01:16 AM
ForgottenMemorie
Is $27x^2+21x-6$ the final answer? I have tried for very long time now (month).

Can someone help Multiply with another question please.
This is urgent.

$(x^2+3x)(4x^2-1.5x+2)$

$(x-^1+6x)(3+x-^0.5+2x^2$

1 is ^ 0.5 is ^
• Jan 8th 2008, 01:46 AM
Quote:

Is 27x^2+21x-6 the final answer?
Yes.

Quote:

(x^2+3x)(4x^2-1.5x+2)
$(x^2+3x)(4x^2-1.5x+2) = x^2(4x^2-1.5x+2)+3x(4x^2-1.5x+2)$
$=x^24x^2+x^2(-1.5x)+x^22+3x4x^2+3x(-1.5x)+3x2$

I think you can continue from here.

To get more than one character in a superscript put {} around what you want at the top eg x^{potato salad tastes better than fish} produces $x^{potatosaladtastesbetterthanfish}$
• Jan 8th 2008, 06:25 AM
ForgottenMemorie
Is that the answer?

$x^4 4+21x^3/2-2.5x^2+6x$

how to do 6 with Math tags?
...................7

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Im stuck on $(x^{-1}+6x)(3+x^{-0.5}+2x^2$

I need to multiply it out.
• Jan 8th 2008, 06:39 AM
colby2152
Well, let's work out what badger provided:

$x^24x^2+x^2(-1.5x)+x^22+3x4x^2+3x(-1.5x)+3x2$

$4x^4+-1.5x^3+2x^2+12x^3-4.5x^2+6x$

$4x^4+10.5x^3-2.5x^2+6x$

It looks like you are right!

Now, on to your other problem...

$(x^{-1}+6x)(2x^2+x^{-0.5}+3)$

$x^{-1}(2x^2+x^{-0.5}+3) + 6x(2x^2+x^{-0.5}+3)$

$2x+x^{-1.5}+3x^{-1}+12x^3+6x^{1.5}+18x$

$2x^3+6x^{1.5}+20x+3x^{-1}+x^{-1.5}+1$
• Jan 8th 2008, 03:34 PM
Use \frac {numerator}{denominator} to get $\frac {numerator}{denominator}$