Since you didn't say what equation you had to do lets put it into point slope form, it's the easiest . If you don't know what it is here it is:
y-y1=m(x-x1)
Now all you do is put the slope, which is 4 and the x and y values of the point into the equation
y-(-3)=4(x-5), simplify
y+3=4(x-5)
Thats all there is to it, come back with a post reply if you need help putting it into a different form.