Question

简便算法计算：（四十分之十九+38）/19 二十分之七/【（六分之五 —三分之二）x3】

简便算法计算：（四十分之十九+38）/19
二十分之七/【（六分之五 —三分之二）x3】
七分之一x十二分之五+十二分之五/五分之七

要简便计算过程

Answer 1

（四十分之十九+38）/19
=（19/40+38)/19
=19/40/19+38/2
=1/40+2
=2又1/40
二十分之七/【（六分之五 —三分之二）x3】
=7/20/[(5/6-2/3)*3]
=7/20/1/2
=7/10
七分之一x十二分之五+十二分之五/五分之七
=1/7*5/12+5/12/7/5
=5/84+7/12
=(5+49)/84
=9/14

Answer 2

（19/40+38）/19
=（19/40）*（1/19）+38/19
=1/40+1/2
=1/40+20/40
=21/40

（7/21）/【（5/6-2/4）x3】
=（7/21）/（5/6-4/6）x3】
=（7/21）/【（1/6)x3】
=（7/21）/（1/2）
=（1/3）x2
=2/3

(1/7)x(5/12)+(5/12)/(7/5)
=(1/7)x(5/12)+(5/12)x(5/7)
=(5/12)x(1/7+5/7)
=(5/12)x(6/7)
=5/14

Answer 3

(19/40 + 38)/19
= 1/40 + 2
= 81/40

7/20 ÷ [(5/6 - 2/3)×3]
= 7/20 ÷ [(5/6 - 4/6)×3]
= 7/20 ÷ [1/6 ×3]
= 7/20 ÷ 1/2
= 7/20 × 2
= 7/10

1/7 × 5/12 + 5/12 ÷ 7/5
= 1/7 × 5/12 + 5/12 × 5/7
= (1/7 + 5/7) × 5/12
= 6/7 × 5/12
= 5/14