A. slope intercept form is y=mx+b where m is your slope and b is your y-intercept. Since it gives you the slope (4) and the y-intercept (-9) all you have to do is plug it into the equation to get y=4x-9
b. This one is a little bit trickier but by no means impossible. the first thing we want to do is find the slope, and in order to do this we take the second y minus the first and divide it by the difference of the second x and the first x. the way that would look in this case is (10-6)/(4-0) and when we simplify this we get 4/4=1
Since our slope is 1, we just need to find the value of y when x=0, In this problem it is given to us with the point (0,6) if we plug both of this into our equation we get y=x+6 (the 1 in front of the x is optional