point slope form

How to write an equation of a line given 2 points

slope intercept form

There are two key facts we need to identify in the graph of a line.

1. slope

2. y-intercept

After we find these, we plug them into the equation.

Slope can be expressed in different ways:

In order to write an equation in Slope Intercept Form, you need 2 things:

1. A slope (m)
2. A y-intercept (b)

It's easy when we are given the slope and the y-intercept....

But, what about when we have a piece missing?

Write an equation of the line in Slope Intercept Form that goes through the point (-3,7) and has a slope of 1/3

• Use the slope formula to find the slope 

• Once you have the slope, choose one of your 2 points (it doesn't matter which you choose - I kind of like to stick with the one on the left)

• Go through the exact same steps we just did in the previous slides

Now we just follow the exact same steps as the previous example.

* Substitute the values for x and y and m into the slope intercept formula (you will answer this on the next slide, so write it down!)

To change from Standard Form to Slope Intercept Form, you solve the equation for y.

• First, add or subtract the "x" term.

• Second, divide by the coefficient (number in front of) y.

• Finally, simplify if you can.

Write 3x + 2y = 6 in slope intercept form