Question 648216
Original equation: {{{(-15/(x+3)(x-7))}}}

The domain of the function is basically all the 'x' points that define that function. When you're asked to find the domain of an equation like the one you provided, you must set everything in the denominator equal to zero, and whatever you get is what makes the function undefined.

Step 1: Set everything in the denominator equal to zero

{{{(-15/(x+3)(x-7))}}}
{{{(x+3)=0}}} and {{{(x-7)=0}}}

Step 2: Solve for 'x' for both equations

{{{(x+3)=0}}} and {{{(x-7)=0}}}
{{{x=-3}}} and {{{x=7}}}

The domain of the function is all real numbers except {{{x = -3}}} and {{{x = 7}}}... because if you plug these numbers back in, they will give you a {{{0}}} in the denominator, making the function undefined.. you can never divide anything by {{{0}}}