Do Now 5/21/10Do Now 5/21/10 Take out HW from last night.Take out HW from last night.

– Text p. 394, #12-23 allText p. 394, #12-23 all

Copy HW in your planner.Copy HW in your planner.– Text p. 394, #24-31 all (8 graphs); #32-38 Text p. 394, #24-31 all (8 graphs); #32-38

evensevens– Quiz sections 8.1 & 8.2 TuesdayQuiz sections 8.1 & 8.2 Tuesday

In your notebook, tell whether the In your notebook, tell whether the ordered pair is a solution of the ordered pair is a solution of the equation. equation.

(4,-12), (10,-19), (-2,-1)(4,-12), (10,-19), (-2,-1) 3x + 2y = -83x + 2y = -8nono yesyes yesyes

HomeworkHomework Text p. 394, #12-23 all Text p. 394, #12-23 all

12) no12) no 13) yes13) yes 14) yes14) yes 15) no15) no 16) yes16) yes 17) yes17) yes 18) yes18) yes 19) no19) no

20) yes20) yes 21) yes21) yes 22) no22) no 23) yes23) yes

ObjectiveObjective

SWBAT practice graphing equations SWBAT practice graphing equations in two variables in two variables

An example of an An example of an equation in two equation in two

variablesvariables is is 2x – y = 5. 2x – y = 5.The The solutionsolution of an equation in two of an equation in two variables, variables, x x andand y y, is an ordered pair , is an ordered pair (x, y)(x, y) that produces a true statement that produces a true statement when substituted into the equation. when substituted into the equation.

Section 8.2 “Linear Equations Section 8.2 “Linear Equations in Two Variables”in Two Variables”

22

44

66

88

1010

00 22 44 66 88 1010 1212

y-axisy-axis

x-axisx-axis

((-2-2,,-10-10))

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

-10-10

-8-8

-6-6

-4-4

-2-2

Graph an EquationGraph an EquationGraph the equation Graph the equation y = 3x - 4y = 3x - 4

xx yy

43 xy

-2-2 -10-10

-1-1 -7-7

((-1-1,,-7-7))

00 -4-4 ((00,,-4-4))

11 -1-1

((11,,-1-1))

22 22

((22,,22))

Graph an EquationGraph an Equation

2y

Solve the equation for y.

STEPSTEP 11

Graph the equation Graph the equation y = 2y = 2..

STEPSTEP 22

Make a table by choosing a few values for x and then finding values for y.

STEPSTEP 33

Plot the points. Notice the points appear on a line. Connect the points drawing a line through them.

x -2 -1 0 1 2

y 2 2 2 2 2

HORIZONTAL LINE y = bHORIZONTAL LINE y = b

Graph an EquationGraph an Equation

1y0x1

1x

Solve the equation for x.

STEPSTEP 11

Graph the equation Graph the equation x = -1x = -1..

STEPSTEP 22

Make a table by choosing a few values for x and then finding values for y.

STEPSTEP 33

Plot the points. Notice the points appear on a line. Connect the points drawing a line through them.

x -1 -1 -1 -1 -1

y -2 -1 0 1 2

VERTICAL LINE x = aVERTICAL LINE x = a

Linear Equation-Linear Equation-an equation whose graph is a linean equation whose graph is a line

Function form-Function form-An equation is in function form An equation is in function form when the equation is solved for when the equation is solved for

y. y.

4x + y = 94x + y = 9

4x + y = 94x + y = 9 y = 9 – 4xy = 9 – 4xSolve the equation for y.

Linear Equation-Linear Equation-an equation whose graph is a linean equation whose graph is a line

Function form-Function form-An equation is in function form An equation is in function form when the equation is solved for when the equation is solved for

y. y.

4x + 3y = 94x + 3y = 9

4x + 3y = 94x + 3y = 9 y = – 4/3x + 3y = – 4/3x + 3Solve the equation for y.

Write the following equations in Write the following equations in function form.function form.

62 yx

xy 62

2

6 xy

xy2

13

32

1 xy

xy3

22

632 yx

xy 263

3

26 xy

23

2 xy

22

44

66

88

1010

00 22 44 66 88 1010 1212

y-axisy-axis

x-axisx-axis

((-2-2,,-10-10))

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

-10-10

-8-8

-6-6

-4-4

-2-2

Graph an EquationGraph an EquationGraph the equation Graph the equation -3x +-3x + y = -4y = -4..

xx yy

xy 34

-2-2 -10-10

-1-1 -7-7

((-1-1,,-7-7))

00 -4-4((00,,-4-4))

11 -1-1

((11,,-1-1))

22 22

((22,,22))

43 yxWrite in function form

22

44

66

88

1010

00 22 44 66 88 1010 1212

y-axisy-axis

x-axisx-axis

((-4-4,,-8-8))

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

-10-10

-8-8

-6-6

-4-4

-2-2

Graph an EquationGraph an EquationGraph the equation Graph the equation -3x + 2y = -4-3x + 2y = -4..

x y

xy2

32

-4-4 -8-8

-2-2 -5-5((-2-2,,-5-5))00 -2-2

((00,,-2-2))

22 11

((22,,11))

44 44

((44,,44))

423 yxWrite in function form

Graph an EquationGraph an Equation

42 xy

xy 24

Solve the equation for y.

STEPSTEP 11

Graph the equation Graph the equation y + 2x = 4y + 2x = 4..

STEPSTEP 22

Make a table by choosing a few values for x and then finding values for y.

STEPSTEP 33

Plot the points. Notice the points appear on a line. Connect the points drawing a line through them.

xx -2-2 -1-1 00 11 22

yy 88 66 44 22 00

Graph an EquationGraph an Equation

3yx2

32 xy

Solve the equation for y.

STEPSTEP 11

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

STEPSTEP 22

Make a table by choosing a few values for x and then finding values for y.

STEPSTEP 33

Plot the points. Notice the points appear on a line. Connect the points drawing a line through them.

xx -2-2 -1-1 00 11 22

yy -7-7 -5-5 -3-3 -1-1 11

HomeworkHomework

Text p. 394, #24-31 all (8 Text p. 394, #24-31 all (8 graphs); #32-38 evensgraphs); #32-38 evens