Multiplying monomials??

Question

i dont understand how to do certain ones, for example,

(-7x^2)(x^4)

or

(2a^2)(8a)

plz explain & dont confuse me more

Answer 1

for example:

(2a^2)(8a)

multiply

2 and 8 which is 16

and a and a^2 is a^3

so the answer is 16a^3

Answer 2

When you are multiplying monomials with the same variables (like two x's), simply add the exponents.  Thus, (x^2)(x^4)=x^6.  

To understand WHY this happens, take it apart.  You know (at least, I hope you know!) that x^2 is merely (x)(x).  Well, think of (x^2)(x^4) as merely being [(x)(x)]*[(x)(x)(x)(x)].  All you have to do is count the x's and make that number your exponent.

If you add numbers to your problem, all you have to do is take the numbers out of the parenthesis and do the same thing:

(-7x^2)(x^4)= -7(x)(x)(x)(x)(x)(x)= -7x^6

So, if you have something like (2a^2)(8a), you can think of it like this:

[(2)(8)]*[(a)(a)(a)] = 16a^3

Answer 3

When multiplying, you add the powers

The first one would be -7x^6 because x^2(x^4) = x^6

The second one would be 16a^3.

It is a^3 because 8a = 8a^1 and you use the same rule.

Answer 4

when you multiply exponents, you add them. just multiply everything else like you would normally and then add the exponents.

so the first one is

-7x^6

the next is 16a^3