Question 782096
Set x=0 to find y intercepts.<P>
y = (0^2 +4(0)-21)/(0+7) = -21/7 = -3<P>
For a rational function, f(x)/g(x), set f(x) = 0.  Solve for x.  That gives you possible x intercepts (roots).  Check each number (possible x intercept) with the original equation, to make sure it doesn't make the denominator 0.  If it does, discard it.<P>
{{{x^2 + 4x -21 = 0}}}<P>
(x+7)(x-3) = 0<P>
x+7 = 0 so x=-7.  But - 7 makes the denominator 0, so discard it.<P>
x-3 = 0 so x = 3<P>
x=3 is the only x intercept.