Algebra 1 Common Core Student Edition, Grade 8-9

Multiplying and Dividing Fractions

To m ultiply two or m ore fractions, m ultiply the num erators, m ultiply the

denom inators, an d simplify th e product, if necessary.

Ex a m p l e 1

Multiply | • |.

Method 1 M ultiply the n u m erato rs an d th e denom inators. Then simplify.

3 5_3*5_15_15-=-3_ 5

7 * 6 7 * 6 42 42 -e 3 14

Method 2 Simplify before multiplying.

3 5 = l • 5 ^ 5

7 ’ 02 7 • 2 14

To m ultiply m ixed num bers, change th e m ixed n u m b ers to im p ro p er fractions and

m ultiply the fractions. Write the p ro d u c t as a m ixed num ber.

Ex a m p l e 2

M ultiply 2§ • i f.

2-. \- = 14.?1 = M = 42

5 13 3 3 3

To divide fractions, change th e division problem to a m ultiplication problem.

Remember that 8 -e \ is the sam e as 8 • 4. To divide m ixed num bers, change

the mixed n u m b ers to im proper fractions an d divide th e fractions.

Ex a m p l e 3

a. Divide5 ' 7

_ 4 7

5 ’ 3

= ?8

15

= lM 15

M ultiply by the reciprocal

o f the divisor.

Simplify.

W rite as a mixed number.

b. Divide 4§-e 7§.

.2 ^ v3 14 38

3 ' 5 3 ' 5

= }£ _5_

3 *3319

35

57

Change to im proper fractions.

Simplify.

Multiply.

Ex e r c i se s

Multiply or divide. Write your answers in sim plest form.

1- I

6. 4;

3

* 4 2 5. 17 3 3. l| • s| 4. 3| •^10 5 s i - 53. o4 3

1. 7 I 2 2 7. q2 c 9 33 • 6 10 8.. 7|

9- 4 * 4 1 0. 4i • 3|

. 1
' 2 12 --T- —5 10 1 3. 2 ^ 3i 1 4. l| -2| 15. 3 ^ i f
•I*CO I C O
17 5 ^ 3l/- 9 5 1j> 5. 3 '«» 8 ’ 4 19. 2 |^ 2 | 20. 6 | 4

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