1. Вычислите: 1) 12/35 : 2/5= 2) 15/17 : 5= 3) 4 : 20/21=4) 8 3/4 : 2 1/3=

1)

35

12

:

5

2

=

35

12

∗

2

5

=

35∗2

12∗5

=

7

6

2) \frac{15}{17} :5=\frac{15}{17}*\frac{1}{5} =\frac{15*1}{17*5} =\frac{3}{17}2)

17

15

:5=

17

15

∗

5

1

=

17∗5

15∗1

=

17

3

3)4:\frac{20}{21} =4*\frac{21}{20}=\frac{4*21}{20} = \frac{21}{5} =4\frac{1}{5} =4,23)4:

21

20

=4∗

20

21

=

20

4∗21

=

5

21

=4

5

1

=4,2

4)8\frac{3}{4}:2\frac{1}{3} =\frac{35}{4}:\frac{7}{3} =\frac{35}{4} *\frac{3}{7} =\frac{5*3}{4}=\frac{15}{4}=3\frac{3}{4}4)8

4

3

:2

3

1

=

4

35

:

3

7

=

4

35

∗

7

3

=

4

5∗3

=

4

15

=3

4

3

=3,75=3,75