Question 178781
{{{(7x-28)/(x^2-16)}}}
:
{{{7(x-4)/(x+4)(x-4)}}}
:
{{{7cross((x-4))/(x+4)cross((x-4))}}}
:
{{{7/(x+4)}}}
:
restrictions are x can be all real numbers except for -4. -4 would put a zero in the denominator and that would make this undefined, therefore it is not allowed.