Question

select the equation in which the slope equals 9 in the y-intercept equals -3

Answer 1

y = mx + b
where 
m = slope
b = y-intercept

y = 9x - 3

Answer 2

y=9x-3, as the equation is originally y=mx+b, m equaling the slope, and b equaling the y intercept. All you really need to do is plug in the numbers :)