Square of 2006 - 2005 * 2007=

Square of 2006 - 2005 * 2007=

=Square of 2006 - (2006-1) (2006 + 1)
=2006 sq. - (2006 sq. - 1)
=2006 square - 2006 square + 1
=1

Help solve a math problem in junior high school
Calculation: 1 / X-1 / (x + 2) - 1 / (2-x)

1/x-1/(x+2)-1/(2-x)
=1/x-1/(x+2)+1/(x-2)
=1/x+4/(x^2-4)
=(x^2+4x-4)/(x^3-4x)

Application problem solving. Need formula and process
1. There is a 40 cm long and 29 cm wide iron plate. Use this iron plate to make a 5 cm deep rectangular box (no cover). How do you think you should use this iron plate to make the volume of the iron box as large as possible?

In the case of a certain depth, the bottom area determines the volume of the iron box. Cut off a 5 * 5 square area at the four corners, and then erect the four sides to make an iron box

A primary school application problem, requires with the formula
Dad bought a sheet of iron 188.4cm in length and 157cm in width, and prepared to make a cylindrical bucket without a cover. The bottom of the bucket is equipped with iron sheet. Dad thought that the capacity of the bucket is the largest. What is the maximum capacity of the bucket?

The iron sheet at the bottom of the barrel is provided with a cover free cover?
Just roll the iron sheet into a circle in the long direction
2 * 3.14 * r = 188.4 it's so hard to calculate r that you can't calculate the volume

(1) The fourth power of (X-Y) (X-Y) and the fifth power of (Y-X)
(2) 2010 power of (- 2) + 2011 power of (- 2)
(3) One eighth of the power of 2011 × 8 of the power of 2012
Who can explain these three questions to me and tell me why I need to calculate like that in every step
Math is really bad. That's all!
10 points to present, explain well, let me understand the words will add points!
The first question is that. How can I not understand it?
(X-Y)(X-Y)^4 (Y-X)^5

(1) The fourth power of (X-Y) (X-Y) the fifth power of (Y-X) = (X-Y) ^ 5 * (- (X-Y) ^ 5) = (X-Y) ^ 10 (2) (- 2) ~ (- 2) ~ (- 2) ~ (- 2) ~ (- 2) ~ (- 2) ~ (- 2) ~ (- 2) ~ (- 2) ~ (- 2) ~ (- 2) ~ (- 2) ~ (- 2) ~ (- 2) ~ (- 2) ~ (- 2) ~ (- 2) ~ (- 2) ~ (- 2) ~ (- 2) ~ (- 2) ~ (- 2) ~ (- 2) ~ (-

This is a practical problem. It needs to be explained in detail
The ticket office of an exhibition stipulates that the retail ticket is 10 yuan per person, and the group ticket for 20 people can enjoy 20% discount. There are about 30 students visiting the exhibition. Some people propose to buy two group tickets, others propose to buy group tickets, and the rest everyone buy individual tickets. Others propose to discuss whether there are more than 36 people. Please tell me what your opinions are

There are x people in the team, 30 of them

It's urgent. It's troublesome~
Xiaoming and Xiaohua have a balloon competition. It is stipulated that one shot will get 1 point and one shot will get - 1 point. After 20 shots, each person will get 14 points and 16 points respectively
Do you know how many shots Xiaoming and Xiaohua hit each other?
Can their score be odd?

Xiaoming shot 17 times, Xiaohua shot 18 times
The score can't be odd, because if the hit is odd, then the miss is odd, odd minus odd is even; if the hit is even, then the miss is even, even minus even is still even. So it can't be odd in any case

1. When I read a small book, I read 25 pages on the first day, which is 25% more than that on the second day. I read one fourth of the whole book on the second day. How many pages are there in this book?
2. It takes 15 minutes for Xiao Ming to ride his bicycle from a to B. the bicycle travels 2 / 13 kilometers every 4 minutes
3. How many minutes does it take to collect a 3-meter-long piece of wood, 3 / 7 meters for each piece, and 2 minutes for each piece?

The first course: let's read page x the next day (1 + 0.25) × x = 25 1.25x = 25 x = 2020 + 25 + (25-20) = 50 (pages). The second course: 2 / 13 = 4 / 26, 1 point = 1 / 26 km, 15 points = 15 / 26 km. The third course: 3 divided by

The process of solving mathematical calculation problems in grade one of junior high school
1.（√5+√3-√2）^2
2.√(10/7)÷(2/3√21/10)×√(1/3)
It means root

1. Formula: (a + B + C) ^ 2
It's a plus B plus C plus 2 ab plus 2 AC plus 2BC
2. All into the root of the form of long calculation

4. It takes 80 hours for one person to plant trees in a certain unit. Now, some people plant trees for 5 hours first. Due to the emergency of the unit, another 2 people have to complete the task of planting trees within 4 hours. The work efficiency of these people is the same. How many people should be arranged to plant trees first

Let's arrange x people first and then x + 2 people
5x+4(x+2)=80x
5x+4x+8=80
5x+4x=72
9x=72
x=8