Algebra I Chapter 4

Warm Up

Directions: Plot and label the following points.

4. A(4, -1) B (5, 0)

5. A (-2, -3) B (-3, -2)

Re-teach

How do you plot an ordered pair? How do you write an ordered pair?

What are quadrants?How do we name them? What is the origin? What is the vertical axis? What is the horizontal axis?

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Practice

Directions: Plot and label the ordered pairs in a coordinate plane.

13. A (0,3) B (-2, 1) C (2, 0)

15. A (4, 1) B (0, -3) C (3, 3)

17. A (-4, 1) B (-1, 5) C (0, -4)

Practice

Directions: Without plotting, identify the quadrant.

19. (5, -3)

21. (6, 17)

23. (-4, -2)

25. (-5, -2)

Warm Up

Complete the following work on the given worksheet.

Re-teach

What is equation form?

How do we rewrite a function to equation form?

-3x + y= 12

2x + 3y = 6

x + 4y = 48

Practice

Directions: Partner with another person and complete the questions on the flashcard.

Closure ---REPEAT

81. 5 + 2 + (-3)

83. -18 + (-10) + (-1)

91. 9x= 3

94. 24 = 8c

97. n/15 = 3/5

Re-teach

Finding x- intercepts and y-intercepts of the graph.

2x + 3y = 6

Solving for x.

Step 1- Write the original equation.Step 2 – Substitute 0 in for y.Step 3- Solve for x.

Re-teach

Finding x- intercepts and y-intercepts of the graph.

2x + 3y = 6

Solving for y. Step 1- Write the original equation.Step 2- Substitute 0 for x. Step 3- Solve for y.

Re-teach

Step 4- After you solve for x and y plot your points.

Step 5- Draw a quick line

Practice

Directions: Partner up and get a piece of construction paper.

Solve the problems for your group and create a poster of the steps on how to solve.

Group 1 Group 2 Group 3x + 3y = 5 x – 2y = 62x + 6y=-243x + 4y = 12 5x – y = 45 -x + 3y =

27

Warm Up

Directions: Plot the points, and draw a line through them. Explain whether the slope is positive, negative or undefined.

12. (6, 9) (4, 3)

17. (0, 0) (-5, 3)

19. (2, -2) (2, -6)

Re-teach

Re-teach

Practice

Directions: Use the slope formula to find the slope and graph the line.

21. (1, 5) (5, 2)

23. (0, -6) (8, 0)

29. (3, 6) (3, 0)

Closure---REPEAT

45. 4b = 26 – 9b

51. 3x + 12 = 5(x + y)

Re-teach

y= kx (model for direct variation)

To Find the constant of variation and the slope.

Ex: y=-5x (0,0) (1,2)

Step 1- Plug the number (-5) in for k. The constant of variation is k=-5

Step 2- Use the slope formula to find the slope.

Practice

12. y=3x

13. -2/5x

15. y=-3x

Re-teach

Examples: Variables x and y vary directly.

x=5; y =20

a. Write an equation that relates x and y.

b. Find the value of y when x = 10

Step 1- Write the model for direct variation.

Step 2- Substitute 5 in for x and 20 in for y.

Step 3- Solve.

Step 4- Substitute 10 in for the value of x.

Graph the equation:

13. y=2x - 1

15. y = 2/3x

33. y = 2Warm Up

Slope-Intercept Form: y = mx + b

Slope is mY intercept is b *** Y IS DIFFERENT THAN THE Y INTERCEPT***

Re-teach

13. y= 6x + 4

21. 12x +4y – 2 = 0

Practice

Re-teach

Graphing Equations-

Parallel lines- have the same slope

Perpendicular lines- have a different slope but the same y intercept

Practice

Functions: Is it or isn’t it?

Re-teach

f(x)g(x)h(x)

What do they mean?21. g(x) = 8x -2 ; x =2, 2 = 0, x = -3

Practice

f(x)g(x)h(x)

Directions: Solve the function. 23. g(x) = 1.25x; x =2, 2 = 0, x = -3

27. 2/5x + 7

Review--Functions

Directions: Graph the function.32. f(x) = -2x + 5

34. h(x) = 5x – 6

38. f(x) 4x + 1

Practice

Directions: Grab a flashcard split into two groups.

Solve problems 56-58 on flashcard.

Review Chapter Test

Scatter PlotsLinear Equations

Quick graphs with interceptsGraphs using slope-intercept formSolving linear equationsSlope of a line

Direct VariationFunctions