Solution equation 1.5 = 0.72/0.4 + 0.03x-0.06/0.3 0.36/0.2-0.09x-0.18/0.9 = 0.05 1.5=0.72/0.4+0.03x-0.06/0.3 0.36/0.2-0.09x-0.18/0.9=0.05

Solution equation 1.5 = 0.72/0.4 + 0.03x-0.06/0.3 0.36/0.2-0.09x-0.18/0.9 = 0.05 1.5=0.72/0.4+0.03x-0.06/0.3 0.36/0.2-0.09x-0.18/0.9=0.05

1.5=0.72/0.4+0.03x-0.06/0.3
Predigesting decimal
1.5=9/5+0.03x-1/5
1.5=0.03x+8/5
0.03x=3/2-8/5
3/100*x=15/10-16/10
3/100*x=-1/10
x=-10/3
0.36/0.2-0.09x-0.18/0.9=0.05
9/5-0.09x-1/5=0.05
0.09x=8/5-1/20
9/100*x=31/20
x=155/9

(4 / 9 + 5 / 6-7 / 18) 1 / 36 is simple
(4 / 9 + 5 / 6-7 / 18) it's easy to divide by 1 / 36

(4 / 9 + 5 / 6-7 / 18) △ 1 / 36
=4 / 9 / 36 1 + 5 / 6 / 36 1-18 7 / 36 1
=4 / 9 × 36 + 5 / 6 × 36 - 7 / 18 × 36
(then make an appointment. Because it's not convenient for the computer to make an appointment, you'll make do with it.)
=16+30-14
=32
Er, if you don't know anything, you are welcome to ask. I hope you can adopt it!

The algorithm is simple and convenient

36 divided by 4 = 9
Four out of seven divided by four equals one out of seven
So it's nine and one in seven

4 / 5 + 1 / 15 + 7 / 25, 5 / 6-1 / 3 + 17 / 18

1、
simple form
=60 out of 75 + 5 out of 75 + 21 out of 75
=75% (60 + 5 + 21)
=86 out of 75
2、
simple form
=15 / 18-6 / 18 + 17 / 18
=18 (15-6 + 17)
=26 out of 18
=13 out of 9

It is known that the ratio of alcohol solution in bottle a and bottle B is 2:3, the volume ratio of alcohol to water in bottle a is 4:3, and the volume ratio of alcohol to water in bottle B is 3:1
What is the volume ratio of alcohol to water

A bottle of alcohol solution is 2 parts
B bottle of alcohol solution is 3 parts
After mixing, it's five portions
The alcohol content in a is 2 × 4 / 7 = 8 / 7
The alcohol content in B is 3 × 3 / 4 = 9 / 4
The mixed alcohol is 8 / 7 + 9 / 4 = 95 / 28
Water: 5-95 / 28 = 45 / 28
After mixing, alcohol: water = 95 / 28:45 / 28 = 19:9

2. The volume ratio of alcohol solution in two bottles is 2:3, the volume ratio of alcohol and water in bottle a is 3:1, and the volume ratio of alcohol and water in bottle B is 4:1
2. The volume ratio of alcohol solution in two bottles is 2:3. The volume ratio of alcohol and water in bottle a is 3:1, and the volume ratio of alcohol and water in bottle B is 4:1. Now, what is the volume ratio of alcohol and water in one bottle

The volume ratio of a and B is 2:3
So let's take the total volume of a and B as 2 and 3, respectively
So it's 2 + 3 = 5
Methyl alcohol 2 × 3 ÷ (3 + 1) = 3 / 2
Ethyl alcohol 3 × 4 (4 + 1) = 12 / 5
So alcohol is 3 / 2 + 12 / 5 = 39 / 10
Water 5-39 / 10 = 11 / 10
So the volume ratio of alcohol to water is 39 / 10:11 / 10 = 39:11

The ratio of alcohol to water is 3:11. The existing alcohol is 30 kg. How many kg of this solution can be prepared?

The ratio of alcohol to water is 3:11, which accounts for 3 / 14
So 30 kg of alcohol comes from 30 * 14 / 3 = 140 kg of this solution

Under a standard atmospheric pressure, use an alcohol lamp to heat water with a mass of 2kg and a temperature of 12 ℃. Suppose that all the heat released during the combustion of alcohol is absorbed by water, then
How many degrees Celsius can the temperature of water rise by burning 25 grams of alcohol completely?

The calorific value of alcohol Q
Let's talk about the method: Q discharge = MQ, find out the heat released by the complete combustion of alcohol, and all of it is absorbed by water. Q suction = q discharge
According to Q suction = cm Δ T, calculate Δ T. discussion: if the rising temperature plus the initial temperature is greater than 100 ℃, because it is under a standard atmospheric pressure, the highest rising temperature is 88 ℃

There are several liquor solutions with 30% alcohol content, which are diluted to 24% alcohol content after adding a certain amount of water
There are several liquor solutions with 30% alcohol content. After adding a certain amount of water, they are diluted to a solution with 24% alcohol content. If the same amount of water is added, what is the alcohol content in the solution?

20%
For example, 30% alcohol and 70% water at the beginning
To 24% of the liquor concentration unchanged, the total amount to reach 125, there is 95% water
If 25% water is added, 120% water will be added
30 / (120 + 30) is 20%
It should be like this

There are several kilograms of 36% alcohol solution, which will be 30% after adding a certain amount of water. If you want to dilute it to 24%, then you need to add several times more water than last time
2. When there is 600g of 20% saline solution, how many g of 5% saline solution can be added to make 15% saline solution?
3. The distance between the two docks is 280km. It takes 14 hours for a ship to go downstream and 20 hours to go upstream?
4. The downstream speed of a ship is 15km / h, and the upstream speed is 10km / h. The two ships go back and forth to wharf A and wharf B for 5 times, which takes 30 hours. How many km is the distance between wharf A and wharf B?

2. Suppose that the concentration of 5% brine solution is XG, then
(20%×600+5%x)/(600+x)=15%
The solution is: x = 300
3. If the ship speed is XKM / h and the water speed is YKM / h, then
280/(x+y)=14
280/(x-y)=20
The solution is: x = 17, y = 3
The fourth question is a round trip. Is it a round trip?
If the distance between the two places is XKM, then
5(x/15+x/10)=30
The solution is: x = 36