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by **weaselgopher** on Fri Jan 30, 2009 3:16 pm

Could someone help me simplify this please? I'm used to the flying X. [(1)/(2a+2b)] + [(a)/(a+b)] which i think gets to [(a+b) + a(2a+2b)]/[(2a+2b)+(a+b)] and then I'm not sure. Thanks for all your help!

**Sponsor**

by **stapel_eliz** on Fri Jan 30, 2009 6:03 pm

weaselgopher wrote:Could someone help me simplify this please? I'm used to the flying X.

Um... What's "the flying X"? :oops:

weaselgopher wrote:[(1)/(2a+2b)] + [(a)/(a+b)] which i think gets to [(a+b) + a(2a+2b)]/[(2a+2b)+(a+b)] and then I'm not sure.

To add these fractions, you need to convert to a common denominator. The two denominators are 2(a + b) and (a + b), so 2(a + b) will be the least (smallest and simplest) common denominator.

The first fraction already has the common denominator. To convert the second fraction to the common denominator, multiply top and bottom by 2:

. . . . . $\left(\frac{a}{a\, +\, b}\right) \left(\frac{2}{2}\right)\, =\, \frac{2a}{2\left(a\, +\, b\right)}$

Then add:

. . . . . $\frac{1}{2\left(a\, +\, b\right)}\, +\, \frac{2a}{2\left(a\, +\, b\right)}\, =\, \frac{\mbox{ ? }}{2\left(a\, +\, b\right)}$

Fill in the numerator to complete the exercise.

Eliz.

The Purplemath Forums

The Flying X: [(1)/(2a+2b)] + [(a)/(a+b)]

The Flying X: [(1)/(2a+2b)] + [(a)/(a+b)]