factor
36-n^2 is difference of 2 perfect squares
a^2-b^2=(a-b)(a+b)
6^2-n^2=(6-n)(6+n)
factor
n^2+16n+60
find what 2 numbers multiply to 60 and add to 16
factors of 60=2,2,3,5
the numbers are 10 and 6
so factored out
(x+6)(x+10)
(x+6)=(6+x)
so the equation is
[(x+6)(x+10)]/[(6+x)(6-x)]=[(6+x)/(6+x)] times (x+10)/((6-x)=1 times (x+10)/(6-x)
the answer is (x+10)/(6-x)
