Let a > 1, if for any x ∈ [a, 2A], y ∈ [a, A2] satisfies the equation logax + logay = 3, then the value set of a is () A. {a|1＜a≤2}B. {a|a≥2}C. {a|2≤a≤3}D. {2，3}

Let a > 1, if for any x ∈ [a, 2A], y ∈ [a, A2] satisfies the equation logax + logay = 3, then the value set of a is () A. {a|1＜a≤2}B. {a|a≥2}C. {a|2≤a≤3}D. {2，3}

It is easy to get y = a3x, monotonically decreasing on [a, 2A], so y ∈ [A22, A2], so A22 ≥ a {a ≥ 2, so B is chosen

If 2 is a root of the equation x & # 178; - C = 0, then what is the constant C? Find out the other roots of the equation

4

What is the length unit of pencil 1? What is the length unit of pencil 8?

One decimeter, eight centimeters

The factory supports the disaster area to make tents. 23 of these tents have been produced. If 210 tents are produced again, 34 of them have been produced. How many tents are there in total

There are a total of X tents, & nbsp; & nbsp; & nbsp; 34x-210 = 23x, 34x-210 + 210 = 23x + 210, & nbsp; & nbsp; & nbsp; & nbsp; 34x-23x = 23x + 210-23x, & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; 112x = 210, & nbsp; & nbsp; 112x △ 112 = 210 △ 112, & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; X = 2520, a: there are a total of 2520 tents

There is an inscribed square in the hemisphere. Try to find the ratio of the volume of the hemisphere to the volume of the cube
An image of a diagonal face
I must draw pictures

Let the edge length of a cube be L
Let R be the radius of the hemisphere
There is a relationship between them
L²+(L/2)²+(L/2)²=R²
It is reduced to r = (√ 6 / 2) L
The volume of the hemisphere is 2 π R & amp; # 179 / 3
The volume of cube is: L & amp; # 179;
The ratio of hemispherical volume to cube volume is as follows
（2πR³/3）：（L³）
=[2π(√6／2)L³/3]：（L³）
=√6π:2

When a car goes from place a to place B, when it is 16 kilometers away from the midpoint, the ratio of the distance traveled to the distance not traveled is 2:3. How many kilometers is the distance between a and B?

Let the distance be x and the time of time be t
（x-16）：t=2x/3:t
（x-16）=2x/3
X = 48 km

A practical problem in the summer vacation of grade six
Xiaoming, Xiaoqiang and Xiaohai take a taxi to go out and share the fare according to the length of the journey. Xiaoming gets off at 1 / 4 of the whole journey and Xiaoqiang gets off at 3 / 5 of the whole journey. Only Xiaohai gets to the destination. Xiaohai pays 37 yuan. How much does Xiaoming and Xiaoqiang pay for Xiaohai?
Thank you

According to the meaning of the question, it should be calculated according to the percentage of the total distance of three people. If the road length is 1, the sum of the total distance of three people is: 1 / 4 + 3 / 5 + 1 = 37 / 20
Xiao Hai paid 37 yuan for the fare
On average, it costs 1 yuan for every 1 / 20 of the total distance
After sharing, Xiaoming is 5 / 20, Xiaoqiang is 12 / 20 and Xiaohai is 20 / 20
Therefore, Xiaoming has to pay 5 yuan for Xiaohai and 12 yuan for Xiaoqiang

In a square with a side length of 6cm, draw the largest circle. The circumference of the largest circle is___ What is the area___ What is the area ratio of the rectangle to the circle

The diameter of the circle is 6cm
Perimeter: 3.14 × 6 = 18.84 cm
Area: 3.14 × (6 △ 2) &# 178; = 28.26 square centimeter
The area ratio of the square to the circle is: 4: π

If a and B are all non-zero rational numbers, what is the value of a / | a | + B / | B | + | ab | / AB

a/|a|+b/|b|+|ab|/ab
1.a>0,b>0
a/|a|+b/|b|+|ab|/ab=1+1+1=3
2.a>0,b

9. A circular track is 400 meters long. B walks 550 meters per minute by bike. A runs 250 meters per minute. The starting point is the same. If a runs for 2 minutes first, B starts again. How many minutes later will the two meet for the second time?
10. When the needle is between 4 o'clock and 5 o'clock, when do the hour hand and minute hand coincide (the direction indicated is the same)? When do they form a straight line (the direction indicated is opposite)? When do they form a right angle?
1. A passenger car and a freight car run from a and B at the same time. The passenger car runs 80km per hour, and the freight car 65km per hour. The freight car starts 51km before the passenger car starts. As a result, the two cars just meet at the midpoint of a and B. how many km did the passenger car travel?
2. The distance between AB and a is 1050 km. A and B trains leave from ab at the same time. Train a runs 60 km per hour, and train B runs 48 km per hour. When train B starts, a pigeon flies out of the carriage and flies to train a at the speed of 80 km per hour. When the pigeon meets with train a, is there thousands of meters left from a?
3. Party A and Party B travel at the same speed. It takes 8 seconds for a train to pass by Party A, and it takes 7 seconds to pass by Party B after 5 minutes. How much more time will Party A and Party B meet?

9. Suppose that Party A and Party B meet for the first time after X minutes of departure
550X+250X+125=400
X=11/32
The second meeting time is 400 / (550 + 250) = 0.5 (min)
11 / 32 + 1 / 2 = 27 / 32 (points)
10. Set 4 o'clock to pass X minutes
The hour hand makes 1 / 12 turn an hour
1 / 12 / 60 laps per minute
Minute hand 1 / 60 turn per minute
At four o'clock
The clock goes 4 / 12 turns
What are the laps in X minutes
4/12+（1/12/60）X=（1/60）X
X=240/11
Then the two stitches meet at 4:240 / 11
240 / 11 is between 21 and 22
It's less than 1:00 at 4:22
2. When car a and pigeon meet, it means that the total distance between car a and pigeon is 1050 km. From this, it can be concluded that the time taken is 1050 / (60 + 80) = 7.5 hours. Car B is 7.5 * 48 = 360 km. Car B is 1050-360 = 690 km away from position a
1.80x [51 ÷ (80-65)] = 272 the speed of 80-65 passenger cars is faster than that of freight cars
51 is the distance that buses take more than trucks
[51 (80-65)] is the travel time of the bus
3. According to (speed sum + speed difference) / 2 = fast; (speed sum - speed difference) / 2 = slow,
It can be known that the speed of the train is (1 / 7 + 1 / 8) / 2 = 15 / 112 per second, conductor
The walking speed of a and B is (1 / 7-1 / 8) / 2 = 1 / 112 per second
So the train speed is 15 times the walking speed
It takes 5 minutes for the train to go from Party A to Party B. It takes 5 * 15 = 75 minutes for the train to walk
During this period, Party A also walked to Party B for 5 minutes, so the train passed by Party B, and the distance between Party A and Party B was 75-5 = 70 minutes
Party A and Party B have the same speed and walk towards each other, so it only takes 35 minutes
Hope to adopt