Question 102142
{{{((x-8)/(x+5))/((x-9)/(x+4))}}} Start with the given expression




{{{((x-8)/(x+5))*((x+4)/(x-9))}}} Multiply the first fraction by the reciprocal of the second fraction




{{{((9-8)/(9+5))*((9+4)/(9-9))}}} Plug in x=9 (this is one of the given values)



{{{((1)/(14))*((13)/(0))}}} Combine like terms. Since you cannot divide by zero, x=9 is not valid for this expression




------------------------------------------------------------



{{{(x-8)/(x+5)}}} Now let's look at the first fraction



{{{(-5-8)/(-5+5)}}} Plug in x=-5 (this is one of the given values)



{{{(-13)/(0)}}} Combine like terms. Since you cannot divide by zero, x=-5 is not valid for this expression



------------------------------------------------------------


{{{(x-9)/(x+4)}}} Now let's look at the second fraction




{{{(-4-9)/(-4+4)}}} Plug in x=-4 (this is one of the given values)



{{{(-13)/(0)}}} Combine like terms. Since you cannot divide by zero, x=-4 is not valid for this expression



So essentially, all 3 of these x values produce denominators of zero. This means they produce undefined results