In the new year's Day celebrations, a supermarket is engaged in beverage promotion activities. It implements the preferential price of buying one box and giving one box free. There are 52 people in class five (one). They bought four boxes, just one box for each person. How many boxes of drinks are there in each box? (use the equation to solve)

In the new year's Day celebrations, a supermarket is engaged in beverage promotion activities. It implements the preferential price of buying one box and giving one box free. There are 52 people in class five (one). They bought four boxes, just one box for each person. How many boxes of drinks are there in each box? (use the equation to solve)

Set X boxes for each box of drinks
4x+4=52
4x=48
x=12
A: there are 12 boxes of drinks in each box

If A-B = 2, then 2 / 1A ^ 2-AB + 2 / 1b ^ 2=
Come on!

2/1a^2-ab+2/1b^2
=2/1(a^2-2ab+b^2)
=2/1(a-b)^2
=2/1×2^2
=2

The distance between a and B is 1700km, and the bus and train depart from the two places at the same time. The bus travels 110km per hour, and the truck travels 80km per hour. After several hours, the distance between the two vehicles is 180km
A and B drive from place a to place B along the same road. Car a starts 3 hours later, car B starts, and car B catches up after 12 o'clock
Limin garment factory plans to produce 2000 sets of costumes for the opening ceremony of the Games in 25 days. Due to the adoption of new technology, it actually makes 20 more sets per day. How many days did it take to complete the task?

68 × 3 = 204 km 204 ／ 12 = 17 68 + 17 = 85 km 2000 ／ 25 = 80 80 + 20 = 100 2000 ／ 100 = 20 days

Given that α and β are two real roots of the equation x ^ 2 + 2x + 5 = 0, then the value of a ^ 2 + a β + 2a is

α. β is the two real roots of the equation x ^ 2 + 2x + 5 = 0
∴a+β=-2,aβ=5
a²+2a+5=0
a²=-5-2a
a^2+aβ +2a
=-5-2a+2a+5
=0

The distance between vehicle a and vehicle B is 150km, and the two vehicles start at the same time. If they travel in the same direction, vehicle B can catch up with vehicle a in 4 hours. If the two vehicles meet in 1.5 hours, the average speed of vehicle a and vehicle B can be calculated
Binary linear equations

The formula is as follows:
In the same direction, B takes 4 hours, and B takes 150 / 4 = 37.5 km more than a per hour
In 1.5 hours, B walks 37.5 * 1.5 more than a = 56.25 km
So a walking for 3 hours is equivalent to walking 150-56.25 = 93.75 km
A: 93.75/3 = 31.25 km / h
B: 31.25 + 37.5 per hour = 68.75 km
The average speed of vehicle a is 31.25 km / h, and that of vehicle B is 68.75 km / h
How to make a linear equation of two variables
The speed of car a is x km / h, and that of car B is y km / h,
4(y-x)=150 ①
1.5(x+y)=150 ②
① The result is Y-X = 37.5
② We get x + y = 100
③+④
2y=137.5 y=68.75
x=100-y=31.25
The average speed of vehicle a is 31.25 km / h, and that of vehicle B is 68.75 km / h

Solve the equation 2 ^ 2x-9 (2 ^ x) + 8 = 0

2^(2x)-9*2^x+8=(2^x-1)(2^x-8)
So, 2 ^ x = 1 or 2 ^ x = 8
So x = 0 or x = 3

The distance between a and B is 1356 km, and the fast and slow trains meet each other 5 hours after driving from a and B. It is known that the speed ratio of the slow train to the fast train is 3:4
How many kilometers do the two cars travel per hour

Suppose the speed of the slow train is 3x and that of the fast train is 4x, because the fast train and the slow train meet each other after 5 hours from a and B respectively, then they can be listed as 3x × 5 + 4x × 5 = 1356, and x = 1356 / 35
The slow speed is 116.2km/h and the fast speed is 155km / h (approximate data)

Record the commercial circulation decimal of 11 ／ 7 as (), and the number on the 2009 digit after the decimal point is ()

57142857 in addition, add the dot of cycle above "142857"
Number two in 2009

The bus and the car drive along the same road in the same direction. The bus travels 60 kilometers per hour. It takes 1.5 hours for the car to start. The car travels 80 kilometers per hour
After a few hours, catch up with the bus on the way? (use equation solution) thank you

When the car starts to travel, the distance the bus has traveled is s = VT = 60 * 1.5 = 90 km
Let t be the travel time when the car overtakes the bus
The equation of equal distance between two cars
V car * t = 90 + V bus * t
80t = 90 + 60t = 4.5H
It can be seen that the car can catch up with the bus 4.5 hours after departure

What is the result of subtracting a from the square root of the square of a? Is it a non negative number or a zero or a positive number or a negative number or a real number

It should be non negative
The first case: when a > 0, (a ^ 2) ^ (1 / 2) - a = A-A = 0
The second case: when a = 0, (a ^ 2) ^ (1 / 2) - a = 0-0 = 0
The third case: when A0
So to sum up, the result should be non negative