Hi Jenny,

The equation of a line in "point-slope form" is given by y - y₁ = m (x - x₁) where m is the slope of the line and (x₁, y₁) is a point that the line passes through.

Using the first of your questions: slope = 4, passing through (1, 3)
m = 4
x₁ = 1
y₁ = 3
Therefore the point-slope form is: y - 3 = 4 (x - 1)

To convert this equation into slope-intercept form (y = mx + b) simply requires that we expand the right hand side to eliminate the brackets, and then isolate y on the left:
y - 3 = 4x - 4
y = 4x - 1
In this form we can tell that the slope of the line, m, is 4 and the y-intercept of the line, b, is -1.

Hope this helps you with the balance of your problems.
Leeanne