39×9/14÷13/14÷18=?9/20×1/2+19/20÷2=?(1/4+1/3÷1/2)÷1/5=?请脱式计算
问题描述:
39×9/14÷13/14÷18=?9/20×1/2+19/20÷2=?(1/4+1/3÷1/2)÷1/5=?请脱式计算
答
39×9/14÷13/14÷18
=39÷18x9/14x14/13
= 2x9/13
=18/13
9/20×1/2+19/20÷2
=9/20×1/2+19/20x1/2
=(9/20+19/20)x1/2
=28/20x1/2
=7/10
(1/4+1/3÷1/2)÷1/5
=(1/4+2/3)÷1/5
= 1/4x5+2/3x5
=5/4+10/3
=55/12