Question

31

1

3

×41

1

2

-11

1

3

×41

1

2

-41.5×20．

Answer 1

31

1

3

×41

1

2

-11

1

3

×41

1

2

-41.5×20
=41

1

2

×（31

1

3

-11

1

3

-20）
=41

1

2

×0
=0．