Question

计算．
[

1

4

-

1

4

÷（4.9-3.4）]×

4

13

6×

3

4

+0.75×2

8

9

×[

7

8

+（

1

4

-0.25）]

2

3

÷

5

8

+

1

3

÷

5

8

．

Answer 1

（1）[

1

4

-

1

4

÷（4.9-3.4）]×

4

13

=[

1

4

-

1

4

÷1.5]×

4

13

=[

1

4

-

1

4

÷

3

2

]×

4

13

=[

1

4

-

1

4

×

2

3

]×

4

13

=

1

4

×[1-

2

3

]×

4

13

=

1

4

×

1

3

×

4

13

=

1

39

；

（2）6×

3

4

+0.75×2
=6×

3

4

+

3

4

×2
=（6+2）×

3

4

=8×

3

4

=6；

（3）

8

9

×[

7

8

+（

1

4

-0.25）]
=

8

9

×[

7

8

+（

1

4

-

1

4

）]
=

8

9

×

7

8

=

7

9

；

（4）

2

3

÷

5

8

+

1

3

÷

5

8

=

2

3

×

8

5

+

1

3

×

5

8

=（

2

3

+

1

3

）×

5

8

=1×

5

8

=

5

8

．