## Writing rational expression in lowest term; help

Quadratic equations and inequalities, variation equations, function notation, systems of equations, etc.
bt786
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### Writing rational expression in lowest term; help

a^3+b^3
-----------
a + b

a^2 - (ab) + b^2

Can anyone explain how to solve this?

Alfred
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### Re: Writing rational expression in lowest term; help

A few good teachers supplied by Google:

FWT
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### Re: Writing rational expression in lowest term; help

$\dfrac{a^3\, +\, b^3}{a\, +\, b}$

$a^2\, -\, ab\, +\, b^2$

Can anyone explain how to solve this?
They're expecting you to remember the special-factoring formula for the sum or difference of cubes. You can find those here. If you apply the sum-of-cubes formula to the top, then you'll get a factor that cancels with the bottom. What's left is what they gave you as the answer.

bt786
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### Re: Writing rational expression in lowest term; help

Thanks!!!
$\dfrac{a^3\, +\, b^3}{a\, +\, b}$

$a^2\, -\, ab\, +\, b^2$