Due to the answer requesting slope intercept form, one shall use the points (3,2) in order to substitute for b. Slope intercept form is formatted in y = mx + b, which m would be your slope, which in this particular problem was given; therefore, y = 1/3x +b.
Now, we shall use points (3,2) as the substitutes for the solution for b, which 3 would be the input and 2 would be y.
Therefore, 2 = 1/3(3) + b
2 = 1 + b, therefore, one would be subtracted from 2 which would give us the answer of b equaling to one. Thus, y = 1/3x + 1