Xiao Li goes from place a to place B by bike, and Xiao Ming goes from place B to place a by bike. They both go at a constant speed. It is known that they set out at 8 am at the same time. By 10 am, they are 36 km apart. By 12 noon, they are 36 km apart. The distance between a and B is calculated

Xiao Li goes from place a to place B by bike, and Xiao Ming goes from place B to place a by bike. They both go at a constant speed. It is known that they set out at 8 am at the same time. By 10 am, they are 36 km apart. By 12 noon, they are 36 km apart. The distance between a and B is calculated

Suppose the distance between a and B is x kilometers. According to the meaning of the question: X − 3610 − 8 = 36 + 3612 − 10, the solution is: x = 108. Answer: the distance between a and B is 108 kilometers

Solving travel and encounter problems with equations
1、
A. B is 12 kilometers away. A goes from a to B, stops at B for half an hour, and then returns to a; B goes from B to a, stops at a for 40 minutes, and then returns to B. It is known that two people start from a and B at the same time, and after 4 hours, they meet on their respective way back. If a's speed is one and a half kilometers faster than B's speed per hour, find their speed
2、
On the circular track, when both of them run clockwise, they meet every 12 minutes. If the speed of both of them does not change, one of them runs counter clockwise and meets every four minutes. How many minutes does it take for each of them to run a lap?

1. Let the velocity of B be x, then the velocity of a is x + 3 / 2
A total of 4-1 / 2 = 7 / 2 hours
B walked 4-2 / 3 = 10 / 3 hours
The total distance they took was three times AB, so
7/2*(x+3/2)+10/3*x=3*12
The solution is x = 9 / 2 = 4.5
So the speed of a is 6 km / h and that of B is 4.5 km / h
2. Let the speed of two persons be x, y and x > y respectively, and the length of a circle is unit 1, then
12(x-y)=1
4(x+y)=1
The solution is x = 1 / 6, y = 1 / 12
So it takes 6 minutes and 12 minutes for each person to run a lap

A passenger car is 190 meters long and a freight car is 290 meters long. The speed ratio of the passenger car to the freight car is 5:3. It is known that the crossing time of two cars is 45 seconds when they are driving in the same direction. How many meters per minute is the speed of the passenger car
How many meters per minute is the speed of the bus

If the speed of freight car is x, the speed of passenger car is 5 / 3x,
From the meaning of the title: 5 / 3x * 45-45x = 190 + 290
The solution is: x = 16 m / s, that is, the speed of the truck is 16 m / s
Then the bus speed is: 16 * 5 / 3 = 26.67 M / s

Party A and Party B walk along the 90cm square in the direction of a-b-c-d-a. Party A walks from a at the speed of 65m per minute, and Party B walks from B at the speed of 72m per minute. When Party B first catches up with Party A, which side of the square is it?
I'm wrong. It's 90m

Unit may be wrong, right to do 90 meters
It can be seen that B is 270 meters behind a, the catching up time is 270 (72-65) = 270 / 7 minutes
At this time, the distance of B is 270 / 7 × 72 △ 90 = 30.86
On da

6.67 - (4.54-3.33) simple calculation method
There are also 10.37-6.24 + 7.63-2.76 simple methods

6.67-(4.54-3.33)
=6.67+3.33-4.54
=10-4.54
=5.46
10.37-6.24+7.63-2.76
=10.37+7.63-(2.76+6.24)
=18-9
=9

1,3,3,9,27,

Starting from the third term, the product of the first two terms is equal to the third number. 9 × 27 = 243

Given that the maximum value of the function y = ax (a > 0 and a ≠ 1) on [1,2] is greater than the minimum value A2, then the value of a is ()
A. 12 or 32B. 32c. 12D. 2 or 3

When a ＞ 1, the function y = ax (a ＞ 0 and a ≠ 1) is an increasing function on [1,2], a2-a = A2 can be obtained from the meaning of the problem, and the solution is a = 32. When 0 ＜ a ＜ 1, the function y = ax (a ＞ 0 and a ≠ 1) is a decreasing function on [1,2], and A-A2 = A2 can be obtained from the meaning of the problem, and the solution is a = 12

1+1/3-7/12+9/20-11/30+13/42-15/56=?
Simple calculation,

1+1/3-7/12+9/20-11/30+13/42-15/56=1+(1/3)-(1/3)-(1/4)+(1/4)+(1/5)-(1/5)-(1/6)+(1/6)+(1/7)-(1/7)-(1/8)=1-(1/8)=7/8

Given 1 / X-1 / y = 3, find x ^ 2 + xy-2y ^ 2 / ax ^ 2-xy + 2Y ^ 2
Seek master, note, there are two ways, please all some
Let's practice writing
Sorry, wrong number. It's 2x-3xy-2y / x-2xy-y
Sorry, I see the next question

∵1/x-1/y=3,
∴y-x=3xy
x^2+xy-2y^2/ax^2-xy+y^2
Changed or wrong

Inequality x2 + AX-1 is greater than 0, and the value range of real number a is obtained

Inequality x2 + AX-1 is greater than 0, and the value range of real number a is obtained
Necessary discriminant = a ^ 2 + 4