first you have to change 1/3 to -3
y=-3x+2
then you have to replace 2 with 'b' because you don't know the y intercept yet
y=-3x+b
then you substitute the point (4,7) into the equation
7= -3(4) + b
7= -12 + b
19 = b
y = -3x + 19 is the equation in slope intercept form
for point slope form:
-3x is still the slope and you replace x and y with the point 4,7
y- 7= -3 (x-4)
