How do you simplify #(n^2 - 10n + 9)/(n^2-3n-54) -: (n^2-8n+7)/(9n^2 +54 n)#?

1 Answer
Jun 22, 2018

#(9n)/(n-7)#

Explanation:

#"factor the numerators/denominators"#

#=((n-1)(n-9))/((n-9)(n+6))-:((n-1)(n-7))/(9n(n+6))#

#"change division to multiplication and invert the second"#
#"fraction, cancelling common factors"#

#=(cancel((n-1))cancel((n-9)))/(cancel((n-9))cancel((n+6)))xx(9ncancel((n+6)))/(cancel((n-1))(n-7))#

#=(9n)/(n-7)#

#"with restriction "n!=7#