How to simplify x^{3} - y^{3 }/ x - y
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Originally Posted by AaPa How to simplify x^{3} - y^{3 }/ x - y look up the factoring pattern for the difference of cubes in your text or online.
$\displaystyle \frac{((x-y)(x^2+xy+y^2))}{(x-y)}$
You should know that: x^3 - y^3 = (x - y)(x^2 + xy + y^2) else you're not ready for this. And your expression needs brackets: (x^3 - y^3) / (x - y)
I knew that x^3 - y^3 = (x - y)(x^2 + xy + y^2) and x^3 - y^3 / (x - y) = (x^2 + xy + y^2) This is what I wanted to prove.
Originally Posted by AaPa I knew that x^3 - y^3 = (x - y)(x^2 + xy + y^2) and x^3 - y^3 / (x - y) = (x^2 + xy + y^2) This is what I wanted to prove. Once more, be CAREFUL with brackets; should be: (x^3 - y^3) / (x - y) = x^2 + xy + y^2 There is NOTHING to prove: simply cancel out the (x - y) terms: see Dobby's post...
Is there a way to find these factors of x^3 - y^3 except try and error?
Google "difference of cubes".
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