4.1- Slope Intercept Form & 4.2 - Point Slope Form

If you are given the slope and the y-intercept use slope-intercept form to write the equation of the line

m = slope

b = y-intercept

if a point has an x-value of 0, the y-value is the y-intercept: (0, b)

If you are given two points you can find the slope using the slope formula and plug the slope in for m.

Then determine which point is the y-intercept to find b.

Plug in the slope for m

Label the point (x₁, y₁) and plug in the values for x₁ and y₁

Then you have written the equation in point-slope form

Step 1: Write the equation in point slope form if not already

Step 2: Distribute (multiply) the slope inside the parenthesis

Step 3: Undo what is happening to y to get y by itself on the left side