You can solve this by using Point-Slope Form which is
(y - y1) = m(x - x1)
The given in this problem is slope (m) = 1/5 and x-intercept = 3 or (3,0).
We will just substitute the given to the formula.
(y - y1) = m(x - x1)
(y - 0) = (1/5) (x - 3)
y = (x/5) - (3/5)
y = (x-3)/5
5y = x - 3
x - 5y = 3 is the equation of the line.
