Slope-Intercept Formula1

GOAL

• Given a line, write a slope-intercept equation.

Slope-Intercept Form

• We need two things, can you guess what they are?

Slope Y-intercept

Equation!

𝑦=𝑚𝑥+𝑏m = Slope

Remember:

b = y-intercept The place where the line crosses the y-axis. Also, when x=0

Example 1

Identify the slope and y-intercept.

• Slope=2• y-intercept=-10

You try!

• Slope and y-intercept?

Example 2

Find y when x=3.

What do we do? Plug 3 in for x.

So: The point (3,-4) is on the line .

You try!

Find y when x=3

Answer: (3,0)

Example 3

Slope and y-intercept?

Slope = 1 Intercept = 0.

Example 4

• Sometimes you will need to solve for y first to get it in the form y=mx+b.

Slope = -2Intercept = 9

Remember

Is equivalent to

Example 5

• Write an equation of the line.

• Slope=?• y=intercept?

Answer:

You try!

You try again!

Homework