Question 764014
Gradients of lines that are perpendicular
have gradients (slopes) that multiply
together to give -1
y = -3x + 1
Gradient (Slope) = - 3
So, gradient of other line = 1/3
Using equation:
y - b = m(x - a)  and (1, 2/3)
y - 2/3 = 1/3(x - 1)
y - 2/3 = 1/3x - 1/3
      y = 1/3x - 1/3 + 2/3
      y = 1/3x + 1/3
OR
Multiply through by 3
3y = x + 1
Hope this helps.
:-)