Question 483463
Divide and simplify
rewrite it:
{{{(r^2+8r)/(r^2+5r-24)}}}
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{{{r/(r+3)}}}
invert the dividing fraction, and multiply
{{{(r^2+8r)/(r^2+5r-24)}}} * {{{(r+3)/r}}}
Factor
{{{r(r+8)/((r+8)(r-3))}}} * {{{(r+3)/r}}} 
look closely, we can cancel r and (r+8), leaving a simple single fraction
{{{1/(r-3)}}} * (r+3)  = {{{(r+3)/(r-3)}}}