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ptebwwong
10-07-2008, 10:15 PM
I need help with this problem:

Simplify.

8a + 2a
__________ ______________
a^2-b^2 a^2-ab

So far this is what I have.
8a + 2a
___________ _____________
(a-b)(a+b) a(a-b)

4
______________
a(a+b)

Is this correct?

Mrspi
10-07-2008, 10:57 PM
I need help with this problem:

Simplify.

8a + 2a
__________ ______________
a^2-b^2 a^2-ab

So far this is what I have.
8a + 2a
___________ _____________
(a-b)(a+b) a(a-b)

4
______________
a(a+b)

Is this correct?

8a 2a
--------- + --------
a^2 - b^2 a^2 + ab

You correctly factored the denominators, which is the first step in finding the common denominator:

8a 2a
----------- + -----------
(a + b)(a - b) a(a + b)

Now...what is the common denominator for the two fractions? It looks to me like the common denominator must contain these factors: a (a + b)(a - b)

Your next step is to rewrite each fraction as an equivalent fraction with a(a + b)(a - b) as its denominator. To accomplish this, you'll need to multiply numerator and denominator of the first fraction by "a", and numerator and denominator of the second fraction by (a - b):

8a(a) 2a(a - b)
----------- + -----------------
(a+b)(a-b)a (a+b)(a-b)a

NOW....the two fractions have the same denominator. ADD the numerators, and put the result over the common denominator.

I will leave it to you to finish the problem.

ptebwwong
10-08-2008, 11:13 AM

-3z-23
________
(z-5)(z+4)

What would the restrictions be for this problem?

Is this correct?

x does not equal 0

Subhotosh Khan
10-08-2008, 01:54 PM