Ask everyone a math problem with a one dimensional equation

A and B cooperate in six days to complete 1 3 of the workload, so A and B respectively complete 1 6 B and C cooperate in two days to complete a quarter of the remaining tasks, so B and C respectively complete (2 3 * 1 4) * 1 2 = 1 12

The rest of the work is completed by three people for 5 days, so A, B and C are completed respectively (2 3 * 3 4) * 1 3 = 1 6

To sum up, A completes 1 6 + 1 6 = 1 3

B completed 1 6 + 1 12 + 1 6 = 5 12 C completed 1 12 + 1 6 = 1 4

According to the principle of distribution according to work, A should get 1 3 * 900 = 300 B should get 5 12 * 900 = 375

C deserves 1 4 * 900 = 225

Hope it helps!

It's a bit difficult to use a one-dimensional equation, but it's a little more troublesome to understand) It takes x days to set a single to complete.

A and B cooperate in 6 days to complete the workload of 1 3

Then B completes the number of days (1 3) 6-1 x = 1 18-1 x B and C cooperate for 2 days to complete the remaining tasks 1 4

Then C completes the number of days (1-1 3) * 1 4 - (1 18-1 x) = 5 72 + 1 x

6+5)/x+(6+2+5)(1/18-1/x)+(2+5)(5/72+1/x)=1

You can forget it yourself later.

1. Suppose the distance between A and B is x.

The flat distance from A to B is 9*(55 60-x 12) (because the unit of speed is hours, but 55 is minutes, so the unit is unified into hours, and it will always be 55 60 hours).

The flat distance from B to A is 8*(

Because in fact, the distance from A to B is the same distance as the distance from B to A, so the distance must be equal.

So. 9*(55 60-x 12) =8*(so the solution is x=3.)

Therefore, the distance between A and B is 3km

2. If the uphill distance is x km, the downhill distance is (2x-14) km.

Column equation: x 28 + (2x-14) 35 + 12 60 = x 35 + (2x-14) 28

Solution: x=42 2x-14=70

So the uphill distance is 42km and the downhill distance is 70km.

The return time of the first question is unclear and there is no solution.

2. If the uphill distance is x km, the downhill distance is (2x-14) km.

Column equation: x 28 + (2x-14) 35 + 12 60 = x 35 + (2x-14) 28

Solution: x=42 2x-14=70

So the uphill distance is 42km and the downhill distance is 70km. end

24 minutes = hours.

In fact, primary school knowledge can solve this problem, let's assume that two people rush from A to B at a speed of 50 kilometers and 75 kilometers per hour respectively. The two of them have been advancing until the slow one arrives, and the faster one has already been 50 kilometers away from him (50, the speed difference between the two is 25 kilometers per hour, 50 25 = 2 (hours), that is, the two people have traveled for 2 hours, and the time of departure for the two people is 10 o'clock, then the distance between the two places = 50 (2 + kilometers, 120 2 = 60 (kilometers per hour).

The full calculation is as follows.

50+75) hours).

50 (2+ kmh).

That is, this person can arrive on time by driving 60 kilometers per hour.

If the number of rentals in the conversation between the two students is x, then there is: 45*x+5=60*(x-1)-10

Solution: x=5

So, to rent a 45-passenger car, you have to be 5+1 to carry all the students. At this time, the fee is: 250*6=1500 yuan.

Rent a 60-passenger car, and you need 5-1 to carry all students. At this time, the fee is: 300 * 4 = 1200 yuan.

So it's more cost-effective to rent 60 passengers, and you need 4 cars at this time.

If there are x people, then (x-5) 45=(x+70) 60

x = 230 people, then, if you rent a 45-seat bus, you need 6, a total of 1500 yuan, rent a 60-seat bus, you need 4, a total of 1200 yuan, so it is more cost-effective to rent a 60-seat bus, you need to rent 4.

Solution: According to the topic, if there are x 45-seater passenger cars, 5 people will not have seats. There is one more passenger car for x 60 seats and there is one more with 10 seats.

45x+5=60x-(60+10)

15x=75

x=5 for a total of 45x+5=230 people.

Sub-situation discussion:1All 45-seater buses. 2.All 60-seater buses.

Situation 1: 230 45 = vehicles) The actual situation is 6 vehicles, 6 * 250 = 1500 (yuan).

Situation 3: 230 60 = vehicles) The actual situation is 4 vehicles 4 * 300 = 1200 (yuan).

A: It is cost-effective to rent a 60-seater bus, you need to rent 4 buses.

If you rent x cars with 45 seats, then 45x+5=60(x-1)-15, you get x=5 cars. There are 230 people in total. Therefore, 6 cars with 45 seats are needed, and the money is 250 * 6 = 1500 yuan.

4 cars with 60 seats, 300 * 4 = 1200 yuan. So the plan: rent a 60-seater for four cars.

If there are a total of x people, then (x-5) 45 = (x + 70) 60 + 1x = 140 people, then, if you rent a 60-seat passenger car, you need 2 cars, a total of 600 yuan, 45 seats 4 taels 1000 yuan.