Question 1009877

{{{(n^2-10n+9)/(n^2+n-90) }}}.....factor and simplify first


{{{(n^2-9n-n+9)/(n^2+10n-9n-90) }}}   


{{{((n^2-9n)-(n-9))/((n^2+10n)-(9n+90)) }}} 

{{{(n(n-9)-(n-9))/(n(n+10)-9(n+10)) }}}


{{{((n-1)(n-9))/((n-9)(n+10)) }}}  


{{{((n-1)cross((n-9)))/(cross((n-9))(n+10)) }}} 


{{{(n-1)/(n+10) }}} 


State the excluded values:

{{{(n^2-10n+9)/(n^2+n-90) }}}

denominator {{{(n^2+n-90) }}} cannot be equal to zero, so exclude the values of {{{n}}} that make denominator equal to zero

since  {{{n^2+n-90=(n-9))(n+10) }}} solutions are the excluded values and they are: {{{n=9}}} and {{{n=-10}}}


so, domain is: 
{ {{{n}}} element {{{R}}} : {{{n<>-10}}} and {{{n<>9}}} }