You can put this solution on YOUR website! Equation of a line with slope 'm' and passing through the point (x1,y1) is
y - y1 = m(x - x1)
From the hypothesis,
m = 3
(x1, y1) = (4, 6)
Plugging in the values in the formula and on further simplification, we get
y = 3x - 6
Hence, option (b) is your answer.