Bellwork Find the x and y intercepts and then graph the line for the following equation: 2x + 6y = 12

2x + 6y = 12 x - intercept Plug 0 in for y 2x + 6(0) = 12 2x = 12 y - intercept Plug 0 in for x 2(0) + 6y = 12 6y = 12 y = 2

2x + 6y = 12 Y X

To be able to find the slope of a line given two points on the line. Today’s Objective To be able to find the slope of a line given two points on the line.

Slope Think of some activities or structures that involve the word slope. Skiing, Stairway, etc..

Slope Slope means rise over run rise run Slope is how much a line rises compared to how much it runs.

Notice the Stair Step effect Y Slope is how much a line rises compared to how much it runs X This line rises 1 and runs -1

The Slope Formula Any two points on a line can be labeled (x1,y1) and (x2,y2) then...

The Slope Formula The formula is y2 - y1 x2 - x1

Label the 2 Points (-1,5)=(x1,y1) Y X (2,2)=(x2,y2)

Let (-1,5) be (x1,y1) and (2,2) be (x2,y2) so… Using the Formula Let (-1,5) be (x1,y1) and (2,2) be (x2,y2) so… 2-5 = -3 = -1 2- -1 3

So..The slope is -1 Y Slope = -1 X

Notice the Stair Step effect Y Slope = -1 X

Positive and Negative Slopes The slope of -1 means that the line rises -1(goes down) and runs 1(goes to the right). Lines with negative slope go up to the left Lines with positive slope go up to the right.

Horizontal and Vertical Lines Horizontal lines have 0 Slope Vertical lines have NO Slope

Horizontal Lines Y Slope = 0 X

Vertical Lines Y No Slope X

Classwork Do worksheet 4.4 HomeWork page 201 (9-28)