Do Now 5/26/10 Take out HW from last night. –Punchline worksheet #125 Copy HW in your planner....

Do Now 5/26/10Do Now 5/26/10Take out HW from last night.Take out HW from last night.

–Punchline worksheet #125Punchline worksheet #125

Copy HW in your planner.Copy HW in your planner.–Text p. 400, #10-30 evensText p. 400, #10-30 evens

In your notebook, define the word In your notebook, define the word INTERCEPTINTERCEPT in your own words. in your own words. Then graph the equation below by making a table. Then graph the equation below by making a table.

2x + 3y = 122x + 3y = 12..

43

2 xy

xx -6-6 -3-3 00 33 66

yy 88 66 44 22 00

HomeworkHomeworkPunchline worksheet #125Punchline worksheet #125

“What Helps Chicks Get Out of Their Shells?”

THE EGG SIT

ObjectiveObjective

SWBAT graph a linear equation SWBAT graph a linear equation using intercepts using intercepts

Section 8.3 “Using Intercepts”Section 8.3 “Using Intercepts”

x-intercept-x-intercept-the x-coordinate of the point the x-coordinate of the point where the line crosses the x-axiswhere the line crosses the x-axis

To find the x-intercept, solve for ‘x’ when ‘y = 0.’To find the x-intercept, solve for ‘x’ when ‘y = 0.’

Find the x-intercept of the graph Find the x-intercept of the graph 2x + 3y = 12 2x + 3y = 12..

2x + 3y = 122x + 3y = 122x + 3(2x + 3(00)= 12)= 12

2x = 122x = 12 x = 6x = 6

y-intercept-y-intercept-the y-coordinate of the point the y-coordinate of the point where the line crosses the y-where the line crosses the y-axisaxis

To find the y-intercept, solve for ‘y’ when ‘x = 0.’To find the y-intercept, solve for ‘y’ when ‘x = 0.’

Find the y-intercept of the graph Find the y-intercept of the graph 2x + 3y = 12 2x + 3y = 12..

2x + 3y = 122x + 3y = 122(2(00)+ 3y= 12)+ 3y= 12

3y = 123y = 12 y = 4y = 4

22

44

66

88

1010

00 22 44 66 88 1010 1212

y-axisy-axis

x-axisx-axis

(0,4)(0,4)

-12-12 -10-10 -8-8 -6-6 -4-4 -2-2

-10-10

-8-8

-6-6

-4-4

-2-2

Graph an Equation Using InterceptsGraph an Equation Using Intercepts

Graph the equation Graph the equation 2 2x + 3y = 12x + 3y = 12..

(6,0)(6,0)

(0,4)(0,4)

(6,0)(6,0)

The x-intercept = 6

The y-intercept = 4

Plot the two intercepts as points and then connect the points using a line.

43

2 xy

xx -6-6 -3-3 00 33 66

yy 88 66 44 22 00

Remember this?

Use Intercepts to Graph an EquationUse Intercepts to Graph an EquationGraph the equation Graph the equation x + 2y = 4 x + 2y = 4..

x +x + 2 2y =y = 4 4

x =x = xx--interceptintercept44

Find the x-interceptFind the x-intercept

x +x + 2(0) 2(0) == 44 0 0 ++ 2 2y =y = 4 4

y =y = y-y-interceptintercept22

x +x + 2 2y =y = 4 4

Find the y-interceptFind the y-intercept

Plot points. The Plot points. The xx--intercept is intercept is 4,4, so plot so plot the point the point (4, 0).(4, 0). The The yy-- intercept is intercept is 2,2, so so plot the point plot the point (0, 2). (0, 2). Draw a line through Draw a line through the points.the points.

Use Intercepts to Graph an EquationUse Intercepts to Graph an EquationGraph the equation Graph the equation 6x + 7y = 42 6x + 7y = 42..

6x +6x + 7 7y =y = 42 42

x =x = xx--interceptintercept77

Find the x-interceptFind the x-intercept

6x +6x + 7(0) 7(0)==4242 6(0) 6(0) ++ 7 7y =y = 42 42

y =y = y-y-interceptintercept66

6x +6x + 7 7y =y = 42 42

Find the y-interceptFind the y-intercept

Plot points. The Plot points. The xx--intercept is intercept is 7,7, so plot the so plot the point point (7,(7, 0).0). The The yy- intercept is - intercept is 6,6, so plot the so plot the point point (0, 6). (0, 6). Draw a line through the points.Draw a line through the points.

Use a Graph to Find InterceptsUse a Graph to Find Intercepts

The graph crosses the The graph crosses the x-x-axis at axis at (2, 0).(2, 0). The The x-x-intercept isintercept is 2.2.

The graph crosses the The graph crosses the yy--axis at axis at (0,(0, –– 1).1). The The y-y-intercept isintercept is – 1. – 1.

The graph crosses the The graph crosses the x-x-axis at axis at (–4,(–4, 0).0). The The x-x-intercept isintercept is –4.–4.

The graph crosses the The graph crosses the yy--axis at axis at (0,(0, 2).2). The The y-y-intercept isintercept is 2. 2.

Use a Graph to Find InterceptsUse a Graph to Find Intercepts

Problem Solving Using Linear EquationsProblem Solving Using Linear EquationsYou are working at a local park and are in charge You are working at a local park and are in charge

of renting skateboards and bikes. You rent bikes for of renting skateboards and bikes. You rent bikes for $8.00 a day and skateboards for $4.00 a day. At the end $8.00 a day and skateboards for $4.00 a day. At the end of the day you have made a profit of $1200. of the day you have made a profit of $1200.

skateboardsskateboards

bike

sbi

kes

4x + 8y = 12004x + 8y = 1200 Write an algebraic Write an algebraic equation to represent equation to represent the situation. Use ‘x’ the situation. Use ‘x’ for skateboards and ‘y’ for skateboards and ‘y’ for bikes. for bikes.

5050

5050 100100 150150 200200 250250 300300

Using the graph, make a table of values to show the different combinations of rentals that could have resulted in a $1200 profit.

100100

150150

HomeworkHomework

Text p. 400, #10-30 evensText p. 400, #10-30 evens