# Slope intercept form

In this video you will learn how to write an equation from a line using the slope intercept form.

Today we are going to look at slope intercept form of a line.
What form is that in y = mx + b ?
m = slope of the line
b = y intercept
What is a y intercept?
It is the point in which the y crosses the x axis.
My y axis is the long axis, I remember it because y is a long letter.
This intercept is 1,2, 3 and I have a y intercept of positive 3.
What is my slope?
I pick two points on the line and I count.
I will go down 3 and over 2.
Basically you draw a right triangle, and we count 1,2,3 down and 1,2 across.
It will be 3/2.
It is slopping down so it will be a negative 3/2
Finally, we just plug and m and a b into our equation.
I will go back over here and for my slope I will plug in negative 3/2
For my y intercept I will put in y intercept I will plug in 3.
There you go, you have your y intercept equation from a graph.
Let's look at an overview
y=mx+b
m = slope
b = y intercept