A and B start from AB and run in opposite directions at the same time. A runs 40 kilometers per hour and B 35 kilometers per hour. The two cars meet at 15 kilometers from the midpoint B how many kilometers are there between the two places? Solve by equation

A and B start from AB and run in opposite directions at the same time. A runs 40 kilometers per hour and B 35 kilometers per hour. The two cars meet at 15 kilometers from the midpoint B how many kilometers are there between the two places? Solve by equation

Arithmetic:
15÷【1/2-35/（40+35）】
=15÷【1/2-7/15】
=15÷1/30
=450 km
Equation:
The distance between the two places is x km
1/2x-35/(40+35)x=15
1/2x-7/15x=15
1/30x=15
x=450
A and B are going from AB to ab at the same time. They meet 40 kilometers away from the midpoint. The whole journey takes 10 hours for a and 15 hours for B. how long is the whole journey?
The time ratio of Party A and Party B to complete the whole journey is 10:15 = 2:3
So the speed ratio is 3:2
When meeting, a drove 3 / (3 + 2) = 3 / 5 of the whole journey
So the whole journey is: 40 / (3 / 5-1 / 2) = 400 km
There is no solution to this problem!
Let the total length be X
The speed of a and B is x / 10 and X / 15 respectively
It takes X / (x / 10 + X / 15) to walk in opposite directions
In the same time, a drives 40 * 2 = 80 km more than B
Equation: X / 10 * x / (x / 10 + X / 15) = x / 15 * x / (x / 10 + X / 15) + 80
The solution is: x = 400km
Time ratio: A: B = 10:15 = 2:3
Speed ratio: A: B = 3:2
Whole course: 3 + 2 = 5, midpoint 5 / 2 = 2.5
Each: 40 / (2.5-2) = 80 (km)
Whole course: 80x5 = 400 (km)
It is known that it takes 8 hours for car a to complete the whole journey and 10 hours for car B to complete the whole journey. There is a distance between a & nbsp; and B & nbsp; two places______ Kilometers
A: A & nbsp; B & nbsp; the distance between the two places is 720 km
The distance between city a and city B is 1200km. Two cars of a and B leave from the two places at the same time. After six hours, the distance is 360km. The speed ratio of car a and car B is known
It's 3:4. How many kilometers does car B travel per hour?
The distance between city a and city B is 1200 km. The two cars run from the two places at the same time. After six hours, the distance is 360 km. It is known that the speed ratio of car a and car B is 3:4. How many kilometers does car B travel per hour?
（1200-360）÷6×4/（4+3）
=840÷6×4/7
=140×4/7
=80 km / h
It costs 132 yuan for a small truck to transport 12 tons of cement at a time, and 162 yuan for a large truck to transport 18 tons at a time
Car 9 times, 1188 yuan, car 10 times, 1620 yuan, a total of 2808 yuan
Please use a group of simple numbers to form a series of numbers and analyze the meaning of the following sentences. Thank you
The sum of each K in the sequence of arithmetic sequence a (n) is still arithmetic sequence, and its tolerance is k ^ 2 times of the original tolerance
I just answered you
I told you how to understand it by setting up a sequence to prove it
In addition to this, if there is anything else, we can only take a special sequence,
For example, an = n. the tolerance is 1
So the sum of the first k terms (let k = 3), a1 + A2 + a3 = 6,
Then the sum of K terms, A4 + A5 + A6 = 15
Then the sum of K terms, a7 + A8 + A9 = 22
Therefore, the sum of every three items is still an arithmetic sequence, and its tolerance is 9 times of the original tolerance
The distance between AB and B is 150km. Vehicle a and B start from ab at the same time and run in opposite directions. The speed of vehicle a is 45km / h, and that of vehicle B is 45km / h
When the distance between the two vehicles is 30km after t hour, then t =?
Meet in 5 / 3 hours
Exercise 1: it takes 16 trucks to load a batch of goods. If it takes 48 trucks to load a batch of goods, it is known that each truck loaded by a large truck is 4 tons more than that loaded by a small truck?
A: the goods are 96 tons
Using the definition of sequence limit to prove that a sequence limit is a certain number
Is it difficult?
Will you take this exam or not?
If necessary, use Taylor expansion
Specific topics use specific methods, sometimes the definition method is a good method, sometimes you can't get out, so you should use it flexibly.
A and B are 1200 meters apart from each other. Car a and B drive from a and B. car a travels 52 kilometers per hour and car B 48 kilometers per hour. How many kilometers did car B travel when they met? Give the process and answer. Thank you
1200 / (52 + 48) = 12 (hours) 12 * 48 = 576 (meters)
1. After several hours, the two cars meet (1200 divided by 52 and 48 equals 12)
2. Then calculate the travel time of car B in 12 hours (the product of 12 and 48)
1200 divided by (52 + 48) is equal to 12 (hours), B goes 12 times 48 is equal to 576 (meters)