Do Now 10/22/13Do Now 10/22/13

Copy HW in your planner.Copy HW in your planner.Text p. 74, #1-3, 8-13, 38, 39, & 41Text p. 74, #1-3, 8-13, 38, 39, & 41

In your journal, describe the In your journal, describe the PROCESSPROCESS (steps (steps you would take) to solve the following question. you would take) to solve the following question. Then solve. What is this an example of?Then solve. What is this an example of?

+ 7 = 10+ 7 = 10 = ?= ?

ObjectiveObjective

SWBAT solve equations using addition SWBAT solve equations using addition and subtractionand subtraction

EQUATION –EQUATION – mathematical sentence formed by mathematical sentence formed by placing an “=” between two placing an “=” between two expressionsexpressions

yy – 8 = 12 – 8 = 12 22 = 14 + z22 = 14 + z

11a = 12111a = 121 5 ÷ x = 30 5 ÷ x = 30

Section 2-5 “Solving Equations Using Section 2-5 “Solving Equations Using Addition & Subtraction”Addition & Subtraction”

EquationEquation

Like a scale, the Like a scale, the left side and right left side and right side must be the side must be the same in order to be same in order to be balanced!balanced!

+ 7 = 10+ 7 = 10Left side Right side

xx

‘‘x’ has to be 3 in order x’ has to be 3 in order to make the equation to make the equation balanced.balanced.

How can you get the “unknown” by How can you get the “unknown” by itself?itself?

““Undo” the operation by using the Undo” the operation by using the INVERSEINVERSE (opposite) operation to (opposite) operation to

both sides of the equation.both sides of the equation.

m + 24 = -18m + 24 = -18

Solving Addition Equations…Solving Addition Equations…

m + 24 = -18m + 24 = -18 – – 24 24 ––2424 m = -42m = -42

Isolate the variable! Get ‘m’ by itself.Isolate the variable! Get ‘m’ by itself.

To get the ‘m’To get the ‘m’by itself get rid ofby itself get rid of““adding 24.”adding 24.”

Do the opposite.Do the opposite.““Subtract 24.”Subtract 24.”

Whatever you do toWhatever you do toone side of the equationone side of the equationyou must do the other side.you must do the other side.

-18 – 24 -18 + (-24) “opp-opp” -42

Check Your Work!Check Your Work!

m + 24 = -18m + 24 = -18m = -42m = -42

((-42-42) + 24 = -18) + 24 = -18

Are both sides equal?Are both sides equal? -18 = -18-18 = -18

Try It OutTry It Out

1). x + 7 = 131). x + 7 = 13

2). -7 = 9 + h2). -7 = 9 + h

3). -3 = x + 73). -3 = x + 7

4). f + 40 = 314). f + 40 = 31

1). 1). (6)(6) + 7 = 13 + 7 = 13

2). -7 = 9 + 2). -7 = 9 + (-16)(-16)

3). -3 = 3). -3 = (-10)(-10) + 7 + 7

4).4).(-9) (-9) + 40 = 31+ 40 = 31

Solving Subtraction Equations…Solving Subtraction Equations…

-13 = y –15-13 = y –15+15 +15 +15 +15

2 = y2 = y

Isolate the variable! Get ‘y’ by itself.Isolate the variable! Get ‘y’ by itself.To get the ‘y’To get the ‘y’by itself get rid ofby itself get rid of““subtracting 15.”subtracting 15.”

Do the opposite.Do the opposite.““Add 15.”Add 15.”

Whatever you do toWhatever you do toone side of the equationone side of the equationyou must do the other side.you must do the other side.

Check Your Work!Check Your Work!

-13 = y – 15 -13 = y – 15 2 = y2 = y

-13 = (-13 = (22) – 15 ) – 15

Are both sides equal?Are both sides equal? -13 = -13-13 = -13

Try It OutTry It Out

1). t - 7 = -31). t - 7 = -3

2). 6 = x – (-3)2). 6 = x – (-3)

3). 40 = r – 21 3). 40 = r – 21

4). -15 = p - 74). -15 = p - 7

1). 1). (4)(4) - 7 = -3 - 7 = -3

2). 6 = 2). 6 = (3) (3) – (-3)– (-3)

3). 40 = 3). 40 = (61) (61) – 21 – 21

4). -15 = 4). -15 = (-8)(-8) - 7 - 7

2424

HomeworkHomework

Text p. 74, #1-3, 8-13, 38, 39, & 41Text p. 74, #1-3, 8-13, 38, 39, & 41