# Help with multiplying exponents

• Feb 25th 2009, 02:45 PM
Jubbly
Help with multiplying exponents
I have these 3 problems I'm struggling on.
The first:
(2y^3)(7x^2)(2y^4)

and

-m^2(4r^3)(12r^4)(5m)

and a word problem
Each side of a cube has a length given by the expression 3x^3 find the volume.

Can you guys show me how to set it up and do the problems step by step?
• Feb 25th 2009, 03:14 PM
Amanda H
In the case of the first question when you are multiplying terms you simply add the exponents provided the variables are the same. In your case the x term will stay the same but you are able to combine the y terms. However the coefficients are multiplied together just like normal numbers.

$2y^3 * 7x^2 * 2y^4$
$= 28x^2y^7$

The second question is delt with in the same way as the first.

For the final question $V = l*b*h$
So $V = 3x^3 * 3x^3 *3x^3$

I'll let you work the other two questions out yourself because it's better for you to do them to make sure you understand. Hopefully I've explained well enough but if you need further help just ask. Feel free to post your answers and I'll check you've done the right thing if you like.
• Feb 25th 2009, 05:48 PM
Jubbly
Thank you!

Now for this equation -m^2(4r^3)(12r^4)(5m)
I got -240m^3r^7 is that right?
• Feb 25th 2009, 07:02 PM