The proportion of the four numbers is 3.5200.7 4 24 36 48 72 2 / 3 1 / 4 3 / 8 17.24.8 3 2 emergency

The proportion of the four numbers is 3.5200.7 4 24 36 48 72 2 / 3 1 / 4 3 / 8 17.24.8 3 2 emergency

0.7／ 3.5 ＝ 4／20 4.8 ／1 7.2＝1/4
24 ／36＝48／72＝2/3

Five out of seven times three out of eight plus five out of eight times three out of seven
Wait a minute. Is there a simple calculation for this problem?

5/7*3/8+5/8*3/7
=5/7*3/8+3/8*5/7
=5/7*（3/8+3/8）
=5/7*3/4
=15/28

3/7 × 49/9 - 4/3 2.8/9 × 15/36 + 1/27 3.12×
3/7 × 49/9 - 4/3
8/9 × 15/36 + 1/27
12× 5/6 – 2/9 ×3
8× 5/4 + 1/4
6÷ 3/8 – 3/8 ÷6
4/7 × 5/9 + 3/7 × 5/9
5/2 -（ 3/2 + 4/5 ）
7/8 + （ 1/8 + 1/9 ）
9 × 5/6 + 5/6
3/4 × 8/9 - 1/3
7 × 5/49 + 3/14
6 ×（ 1/2 + 2/3 ）
8 × 4/5 + 8 × 11/5
14.31 × 5/6 – 5/6
15.9/7 - （ 2/7 – 10/21 ）
5/9 × 18 – 14 × 2/7
4/5 × 25/16 + 2/3 × 3/4
14 × 8/7 – 5/6 × 12/15
17/32 – 3/4 × 9/24
3 × 2/9 + 1/3
5/7 × 3/25 + 3/7
3/14 ×× 2/3 + 1/6

3 / 7 × 49 / 9 - 4 / 3 = 7 / 3 - 4 / 3 = 18 / 9 × 15 / 36 + 1 / 27 = 10 / 27 + 1 / 27 = 11 / 2712 × 5 / 6 – 2 / 9 × 3 = 10-2 / 3 = 9 and 1 / 38 × 5 / 4 + 1 / 4 = 10 + 1 / 4 = 10 and 1 / 4 6 △ 3 / 8 – 3 / 8 △ 6 = 6 × 8 / 3 – 3 / 8 × 1 / 6 = 16-1 / 16 = 15 and 15 / 164 / 7 × 5 /

3/7 × 49/9 - 4/3 8/9 × 15/36 + 1/27 12× 5/6 – 2/9 ×3 8× 5/4 + 1/4
3/7 × 49/9 - 4/3
8/9 × 15/36 + 1/27
12× 5/6 – 2/9 ×3
8× 5/4 + 1/4

3/7 × 49/9 - 4/3 =1
8/9 × 15/36 + 1/27 =13/27
12× 5/6 – 2/9 ×3 =28/3
8× 5/4 + 1/4=41/4

Of the two bottles a and B, bottle a contains 180 kg of salt water, including 18 kg of salt; bottle B contains 220 kg of original water and now 30 kg of salt

Which concentration do you want to calculate?
A: 18 / 180 = 0.1
B: 30 / (30 + 220) = 0.12
Naturally, the concentration of B is high, ha ha

When there is a barrel of alcohol, pour out 8 liters, fill it with water, then pour out 4 liters, and fill it with water. At this time, the ratio of alcohol to water is 18:7, and calculate the volume of the barrel

Let the volume of the barrel be x liter, then the equation is set up according to the meaning of the title: then x-8-x − 8x × 4 = x × 1818 + 7, the solution is X1 = 40, X2 = 207 < 8 (rounding off). The test shows that x = 40 is in line with the meaning of the title, so the volume of the barrel is 40 liter

When there is a barrel of alcohol, pour out 8 liters, fill it with water, then pour out 4 liters, and fill it with water. At this time, the ratio of alcohol to water is 18:7, and calculate the volume of the barrel

Let the volume of the barrel be x liter, then the equation is set up according to the meaning of the title: then x-8-x − 8x × 4 = x × 1818 + 7, the solution is X1 = 40, X2 = 207 < 8 (rounding off). The test shows that x = 40 is in line with the meaning of the title, so the volume of the barrel is 40 liter

There is a bucket of pure alcohol. Take out 8 liters of it and fill it with water. Take out 4 liters of mixed solution and fill it with water. At this time, the ratio of alcohol to water in the bucket is 18
There is a bucket of pure alcohol. Take out 8 liters of it and fill it with water. Take out 4 liters of mixed solution and fill it with water. At this time, the ratio of alcohol to water in the bucket is 18:7?

11x ^ 2-216x + 576, the solution is the answer

There is a bucket of alcohol. Pour out 5 liters and fill it with water. Then pour out 5 liters and fill it with water. At this time, the ratio of alcohol to water is 16 ∶ 25. Calculate the volume of the bucket (write the process)

Let X be the volume of residual alcohol and y be the volume of water, because alcohol: water = 16:25, y = 5 + 5-5 / 2 = 7.5, x = 4.8, v = 4.8 + 5 + 5 / 2 = 12.3l

There is a bucket of alcohol. Pour out 8 liters and fill it with water. Then pour out 4 liters and fill it with water. At this time, there is 10 liters of water in the alcohol solution. Calculate the volume of this bucket

Set capacity X Poured water: 8 + 4 = 12 The volume fraction of water when pouring out is: 8 / X Then pour out water: (8 / x) * 4 = 12-10 = 2 The solution is x = 16