01/05/11 Fraction and Decimal Equations

Today’s Plan:-Fraction and Decimal Equations-Assignment

Learning Target:

-I can solve fraction and decimal equations

Warm UpSolve.

1. x – 16 = 8

2. 7a = 35

3.

4. y + 21 = 31

x = 24

a = 5

x = 132x12

= 11

y = 10

01/05/11 Fraction and Decimal Equations

Today’s Plan:-Fraction and Decimal Equations-Assignment

Learning Target:

-I can solve fraction and decimal equations

Correct HomeworkPg 187 #1-6, 31-43

Solve. Write the answer in simplest form.

Additional Example 1A: Solving Equations by Adding or Subtracting

A. x – 37

= 57

x – 37

= 57

x – 37

+ 37

= 57

+ 37

Add to isolate x.

x = 87

=1 17

Simplify.

Course 2

4-12 Solving Equations Containing Fractions

Solve. Write the answer in simplest form.

Try This: Example 1A

A. x – 38

= 78

x – 38

= 78

x – 38

+ 38

= 78

+ 38

Add to isolate x.

x = 10 8

= 1 14

Simplify.

Course 2

4-12 Solving Equations Containing Fractions

Solve. Write the answer in simplest terms.

Additional Example 2A: Solving Equations by Multiplying

A. 38

x = 14

38

x =. 83

14

. 83

2

1

=x 23

Multiply by the reciprocal of .38

Then simplify.

38

= 14

x =

To undo multiplying by

Remember!38 , you can divide by 3

8or multiply

by its reciprocal, 83

.

Course 2

4-12 Solving Equations Containing Fractions

Additional Example 2B: Solving Equations by Multiplying

B. 4x = 89

89

x =. 14

89

. 141

2

x = 29

4x =

4

Multiply by the reciprocal of 4.

Then simplify.

Solve. Write the answer in simplest terms.

Course 2

4-12 Solving Equations Containing Fractions

Solve. Write the answer in simplest terms.

Try This: Example 2A

A. 34

x = 12

34

x =. 43

12

. 43

2

1

=x 23

Multiply by the reciprocal of .34

Then simplify.

34

= 12

x =

Course 2

4-12 Solving Equations Containing Fractions

Try This: Example 2B

B. 3x = 67

67

x =. 13

67

. 131

2

x = 27

3x =

3

Multiply by the reciprocal of 3.

Then simplify.

Solve. Write the answer in simplest terms.

Course 2

4-12 Solving Equations Containing Fractions

Solve.

Additional Example 2A: Solving Equations by Multiplying and Dividing

Course 2

4-6 Solving Equations Containing Decimals

A. x4.8 = 5.4

x4.8 = 5.4

4.8x 4.8 =· 5.4 · 4.8 Multiply to isolate x.

x = 25.92

Solve.

Additional Example 2B: Solving Equations by Multiplying and Dividing

Course 2

4-6 Solving Equations Containing Decimals

B. 9 = 3.6d

9 = 3.6d

93.6

3.69

2.5 = d

=3.6d3.6

= d

Divide to isolate d.

Think: 9 ÷ 3.6 = 90 ÷ 36

Solve.

Try This: Example 2A

Course 2

4-6 Solving Equations Containing Decimals

A. x3.5 = 2.4

x3.5 = 2.4

3.5x 3.5 =· 2.4 · 3.5 Multiply to isolate x.

x = 8.4

Solve.

Try This: Example 2B

Course 2

4-6 Solving Equations Containing Decimals

B. 9 = 2.5d

9 = 2.5d

92.5

2.59

3.6 = d

=2.5d2.5

= d

Divide to isolate d.

Think: 9 ÷ 2.5 = 90 ÷ 25

Solve.

1. x – 14.23 = 19.5

2. 12.6c = –103.32

3.

4. m + 12.97 =–14.35

5. The French Club is selling coupon books for $8.25 each. How many books must be sold to bring in $5,940?

c = –8.2

x = 33.73

Insert Lesson Title Here

x = 56.73

Course 2

4-6 Solving Equations Containing Decimals

x9.3

= 6.1

720 books

m = –27.32

Lesson Quiz

Solve. Write each answer in simplest form.

1.

2.

3.

4.

1

Insert Lesson Title Here

x – 38 =

58

y + 716

= 1932

x4

= 37

34

=x 1 13

5. Over the course of a week, Marissa ate some apples from a basket on the table. She left 20 apples in the basket. This was five-eights the number of apples her mother had picked earlier in the week. How many apples did her mother pick? 32

Course 2

4-12 Solving Equations Containing Fractions

5 32

12 7

5 7

or 1

16 9

7 9

or 1