<s>[INST] Solve quadratic fraction I would like to simplify the fraction
$$\frac{x^2-2x}{x^2+x-6}$$
I know from Mathematica that it should equal $\frac3{3x}$ but how do I get there? 
 [/INST] The numerator factors as $x^{2}-2x=x(x-2)$. 
By the quadratic formula, the denominator has roots $2$ and $-3$. So the denominator factors as $x^{2}+x-6=(x-2)(x+3)$.
Hence 
$\frac{x^{2}-2x}{x^{2}+x-6}=\frac{x(x-2)}{(x-2)(x+3)}=\frac{x}{x+3}$.
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