SOLUTION: State the excluded values for the following expression. Then simplify the expression. Please explain and show work. (n^2-10n+9)/(n^2+n-90)

Algebra ->  Radicals -> SOLUTION: State the excluded values for the following expression. Then simplify the expression. Please explain and show work. (n^2-10n+9)/(n^2+n-90)      Log On


   

Question 1009877: State the excluded values for the following expression. Then simplify the expression. Please explain and show work.
(n^2-10n+9)/(n^2+n-90)
Found 2 solutions by It is costly, MathLover1:
Answer by It is costly(175) About Me  (Show Source):
Answer by MathLover1(20849) About Me  (Show Source):
You can put this solution on YOUR website!

%28n%5E2-10n%2B9%29%2F%28n%5E2%2Bn-90%29+.....factor and simplify first

%28n%5E2-9n-n%2B9%29%2F%28n%5E2%2B10n-9n-90%29+

%28%28n%5E2-9n%29-%28n-9%29%29%2F%28%28n%5E2%2B10n%29-%289n%2B90%29%29+
%28n%28n-9%29-%28n-9%29%29%2F%28n%28n%2B10%29-9%28n%2B10%29%29+

%28%28n-1%29%28n-9%29%29%2F%28%28n-9%29%28n%2B10%29%29+

%28%28n-1%29cross%28%28n-9%29%29%29%2F%28cross%28%28n-9%29%29%28n%2B10%29%29+

%28n-1%29%2F%28n%2B10%29+

State the excluded values:
%28n%5E2-10n%2B9%29%2F%28n%5E2%2Bn-90%29+
denominator %28n%5E2%2Bn-90%29+ cannot be equal to zero, so exclude the values of n that make denominator equal to zero
since n%5E2%2Bn-90=%28n-9%29%29%28n%2B10%29+ solutions are the excluded values and they are: n=9 and n=-10

so, domain is:
{ n element R : n%3C%3E-10 and n%3C%3E9 }