The two trains leave 500 kilometers apart at the same time, but they don't meet each other four hours later. They are 20 kilometers apart. It is known that car a travels 65 kilometers per hour, and how many kilometers does car B travel per hour?

The two trains leave 500 kilometers apart at the same time, but they don't meet each other four hours later. They are 20 kilometers apart. It is known that car a travels 65 kilometers per hour, and how many kilometers does car B travel per hour?

(500-20) △ 4 = 480 △ 4 = 120 (km); 120-65 = 55 (km); a: car B runs 55 km per hour
The two trains leave 500 kilometers apart at the same time, but they don't meet each other four hours later. They are 20 kilometers apart. It is known that car a travels 65 kilometers per hour, and how many kilometers does car B travel per hour?
(500-20) △ 4 = 480 △ 4 = 120 (km); 120-65 = 55 (km); a: car B runs 55 km per hour
Train a and train B leave 1070 kilometers apart at the same time. Train a travels 90 kilometers per hour. After five hours, they have to travel a total of 160 kilometers to meet each other. How many kilometers does train B travel per hour?
(1070-160) △ 5-90, = 910 △ 5-90, = 182-90, = 92 (km); a: car B travels 92 km per hour
The two trains leave 500 kilometers apart at the same time, but they don't meet each other four hours later. They are 20 kilometers apart. It is known that car a travels 65 kilometers per hour, and how many kilometers does car B travel per hour?
(500-20) △ 4 = 480 △ 4 = 120 (km); 120-65 = 55 (km); a: car B runs 55 km per hour
When transporting a batch of goods by truck, each truck carries 4 tons, and there are still 8 tons left. Each truck carries 5 tons, and there are still one truck and 3 tons of goods left. How many trucks are there in this fleet? How many tons of goods are there?
Let's assume that there are x cars in this fleet
4x+8=5(x-1)+3
4x+8=5x-5+3
5x-4x=8+2
x=10
The cargo is 4x10 + 8 = 48 tons
There are x cars
Then 4x + 8 = 5 (x-1) + 3
4X+8=5X-2
X=10
There are 10 cars
The cargo is 4 × 10 + 8 = 48 tons
Have a good time
Suppose the fleet has x cars, then 4x + 8 = 5 (x-1) + 3, and we get x = 10, so the fleet has 10 cars, and the goods have 4 * 10 + 8 = 48 tons.
Let's say that there are x cars in this fleet.
4x+8=5(x-1)+3
4x+8=5x-5+3
5x-4x=8+2
x=10
There are 10 cars
The cargo is 4x10 + 8 = 48 tons
When class one of grade five is preparing for the spring outing, the head teacher asks the class leader to buy 40 bottles of mineral water. The price of each bottle of mineral water is 1.2 yuan. The preferential method of supermarket a is to give 2 bottles for 10 bottles, but not for less than 10 bottles. The preferential method of supermarket B is to buy more than 10 bottles, including 0.2 yuan for 10 bottles. Which mineral water is more cost-effective
Scheme A: buy 34 bottles, of which 30 bottles get 6 free. Price: 34 * 1.2 = 40.8 yuan
Plan B: buy 40 bottles, the price is 40 * (1.2-0.2) = 40 yuan
Scheme B is cheap
The distance between a and B is 360 km. The trucks and buses start from the two places at the same time and run in opposite directions. After 4.5 hours, the two vehicles meet. It is known that the speed ratio of the trucks and buses is 7:9. How many kilometers per hour do the trucks and buses run?
The speed sum of freight cars and passenger cars is 360 △ 4.5 = 80 km / h
And then it's distributed proportionally
80 × 7 / (7 + 9) = 35 km / h
The bus runs 35 × 9 / 7 per hour = 45 km
Solution: suppose the speeds of freight cars and passenger cars are respectively XKM / h and YKM / h. We get 4.5 (x + y) = 360, 9x = 7Y, so x = 35 and y = 45. Answer: freight cars are 35km / h and passenger cars are 45km / h
The calculation of the second radical of the eighth grade mathematics
How to add
How to multiply the number under the root of an integer * by the number under the root of an integer
4 √ 5 * 8 √ 3 = 32 √ the multiplication outside the root sign and the multiplication inside the root sign are further simplified
√5-√6-√20+√2/3+√9/5
=√5-√6-2√5+（√6）/3+(3√5)/5
=-(2√5)/5-(2√6)/3
First simplify the root sign, then add and subtract the same root sign
The multiplication of numbers under the root sign can also be rationalized by the numerator and denominator. You can give a specific example to illustrate 4 * root sign, 5 * 8 * root sign, 3... And addition. I don't know what you mean. Can you describe it in Chinese? thank you! 4√5*8√3=？ √5-√6-√20+√2/3+√9/5=？ 32 times root sign 15 simplified and then generalized: finally, it is equal to minus 2 / 5 times root sign 5 minus 2 / 3 times root sign 6 √ 5 - √ 6 - √ 20 + √ 2 / 3 + √ 9 / 5 =? Well, my second sentence is the second question
You can give a specific example to ask: 4 * radical, 5 * 8 * radical, 3... And addition
A batch of goods, 4 tons per car, there are 8 tons left. If 4.5 tons per car is just finished, how many cars are there?
With equations, there are formulas
With X cars, 4.5x-4x = 8 and x = 16
The students went on a spring outing and bought two boxes of mineral water, 24 bottles in each box. The salesperson stipulated that one bottle of mineral water could be exchanged for every three empty bottles. How many bottles of water could they drink at most?
48+16+5+1+1=71