(x+9)/(x) * (x^2-6x)/(x^2+3x-54)
Factoring the second fraction, we have
[x(x - 6)] / [ (x - 6) ( x + 9) ] the x - 6 terms "cancel" and we're left with
x/ (x + 9) so we have
(x + 9) / x * ( x) / ( x+ 9) = 1 !!!!!
[ as long as x not equal to 0, 6, or -9 ]