这样计算的:
4/5÷[8×(1/2-2/5)]
=4/5÷(8x1/10)
=4/5÷4/5
=1
[1-(1/4+3/8)]÷1/4
=(1-5/8)x4
=3/8x4
=3/2
9×13×(5/13+5/9)
=9x13x5/13+9x5/9x13
=9x5+5x13
=5x(9+13)
=5x22
=110
4/5÷[8×(1/2-2/5)]
=4/5÷[8×1/10]
=4/5÷4/5
=1
[1-(1/4+3/8)]÷1/4
=[1-5/8]÷1/4
=3/8÷1/4
=3/2
9×13×(5/13+5/9)
=9×13×5/13+9×13×5/9
=45+65
=110