​Finding Slope

• From an equation

• From a graph

• From two points

• From a table

Slope-intercept form is written as y = mx + b,

where m is the slope.

Let's look at a few examples.

​

Finding Slope from an Equation.

Example 1:

Finding Slope from an Equation.

m =

Example 2:

m =

Example 3:

m =

To find slope from a graph we 1) choose two points on the line, and 2) count the rise and run from one point to the next.

Let's look at a few examples.

​

Finding Slope from a Graph.

Example 1:

Finding Slope from a Graph.

m =

Example 2:

m =

Example 3:

m =

To find slope from two points we 1) choose two points, 2) label the coordinates x₁, y₁ and x₂, y₂, 3) plug the values into slope formula and solve.

Let's look at a few examples.

​

Finding Slope from Two Points.

Example 1:

(2, 5) and (4, 13)

Finding Slope from Two Points.

m =

Example 2:

(-1, -3) and (2, -5)

m =

Example 3:

(3, 5) and (7, 13)

m =

Finding slope from a table is very similar to finding slope from two points. 1) Choose two points from the table, 2) label the the coordinates x₁, y₁ and x₂, y₂, 3) plug the values into slope formula and solve.

Another option is finding a pattern in the table.

Let's look at a few examples.

​

Finding Slope from a Table.

Example 1:

Finding Slope from a Table.

m =

Example 2:

m =

Example 3:

m =

​Finding y-intercept

• From an equation

• From a graph

• From a point or table

In the slope-intercept form equation, y = mx + b,

b is the y-intercept.

Let's look at a few examples.

​

Finding y-intercept

from an Equation.

Example 1:

Finding y-intercept

from an Equation.

b =

Example 2:

b =

Example 3:

b =

To find the y-intercept of a graph, we locate the point where the line crosses the y-axis.

Let's look at a few examples.

​

Finding y-intercept from a Graph.

Example 1:

Finding y-intercept from a Graph.

b =

Example 2:

b =

Example 3:

b =

To find the y-intercept from a point or table, we have to look for the value of y when x is 0.

Let's look at a few examples.

​

Finding y-intercept from a point or a table.

​(0, 9)

Once you find the slope and y-intercept, you can write an equation in slope intercept form.

Let's try.

​

Writing an Equation.

Example 1:

Writing an Equation.

m=

b =

y=

Example 2:

Example 3:

m=

b =

y=

m=

b =

y=

Let's review all we've learned...