1.(-81又18/25)÷20又1/4 2.1/60÷(1/4-1/5+1/3)
1个回答

1.(-81又18/25)÷20又1/4

=-81又18/25÷81/4

=-81÷81/4-18/25÷81/4

=-4-8/225

=-4又8/225

2.1/60÷(1/4-1/5+1/3)

=1÷(1/4×60-1/5×60+1/3×60)

=1÷(15-12+20)

=1÷23

=1/23

3.(1/4-1/5+1/3)÷1/60

=1/4×60-1/5×60+1/3×60

=15-12+20

=23

4.(-1/42)÷(1/6-3/14+2/3-2/7)

=-1÷(1/6×42-1/14×42+2/3×42-2/7×42)

=-1÷(7-3+28-12)

=-1÷20

=-1/20

5.[1又1/24-(3/8+1/6-3/4)×24]÷(-5)

=[1又1/24-(3/8×24+1/6×24-3/4×24)]÷(-5)

=[1又1/24-(9+4-18)]÷(-5)

=[1又1/24+5]÷(-5)

=25/24÷(-5)+5÷(-5)

=-5/24-1

=-1又5/24

6.|-5又1/2|×(1/3-1/2)×3/11÷(1-1/4)

=5又1/2×(-1/6)×3/11÷3/4

=-11/12×3/11÷3/4

=-1/4÷3/4

=-1/3