Find the y-intercept(s),k if any for the equation y=x^2-16

If you follow the y=mx+b form m is always your slope and b is always your y-intercept so since this equation is in that form then you can see that 16 is your y-intercept! Since it is at the end of the equation, because if its in that proper form then your last number is always your "b" (in other words, the last number is always the y-interept in every equation like that) 

Hope I helped you:)