Read "reading for the rise of China" and received profound education

Read "reading for the rise of China" and received profound education

After reading reading reading for the rise of China, I was deeply educated
Lack of subject "I"

How to correct the wrong sentences: after reading this book, I received a profound education

In a word, it's not right to have an "Shi"

1+2+3+4+5+6+7+8+9+10+11+12…… 100 =? Formula

5050

Zero point 5x plus two fifths equals zero point eight minus zero point zero eight

0.5x +2/5x = 0.8 - 0.08
0.9x = 0.72
x = 0.8

Three fourths of an hour is a fraction of a minute
The main question is how to solve this problem

Unit conversion
1 hour = 60 minutes
So: 3 / 4 hours = 3 / 4 × 60 minutes = 45 minutes, if the result is an integer, it is written as a fraction with denominator of 1, 60 / 1 hours

What simple expressions can A1 * a1 + A1 * A2 + A1 * A3 + A2 * A2 + A2 * A3 + a3 * A3 be used to express the above mathematical expressions, such as matrix operation

This is the quadratic form, which has a standard matrix representation
[A1, A2, A3] * [1, 1/2, 1/2; 1/2, 1, 1/2; 1/2, 1/2, 1] * [A1; A2; A3]
Of course, if only a simple expression is needed, the middle matrix can also be used without symmetric matrix, for example
[A1, A2, A3] * [1, 1, 1; 0, 1, 1; 0, 0, 1] * [A1; A2; A3]

The solution and process of several equation problems
3x-y+z=4 2x+3y-z=12 x+z+y=6
y=2x-7 5x+3y+2z=2 3x-4z=4

1.3x-y+z=4①
2x+3y-z=12②
x+y+z=6③
①+②=5x+2y=16④
②+③=3x+4y=18⑤
④ Multiply 2 - 5 to get 7x = 14
x=2
y=3
z=1
2. Take y = 2x-7 into 5x + 3Y + 2Z = 2 to get: 11x + 2Z = 23
We get x = 2
y=-3
z=1/2

If the radius of a circle increases by 1 / 5, how many parts of its area will it increase?

(1+1/5)²-1=11/25

Given the function f (x) = x / 1 + X, find f (0) + F (1) + +f(100）+f（1/2）+f（1/3）+… The value of F (1 / 100)
The answer is 199 / 2

F (0) = 0 / (1 + 0) = 0, f (1) = 1 / (1 + 1) = 1 / 2F (x) = x / (1 + x), then f (1 / x) = (1 / x) / (1 + 1 / x) = 1 / (x + 1) f (x) + F (1 / x) = x / (1 + x) + 1 / (x + 1) = (x + 1) / (x + 1) = 1F (0) + F (1) +... + F (100) + F (1 / 2) + F (1 / 3) +... + F (1 / 100) = f (0) + F (1) + [f (2) + F (1 / 2)] + [f (3) + F (1 / 3

4X (x-5.07) + x = 8.63 18-4x = 2x + 3 (2X-4) * 3 = (x + 5) * 4 how to solve 0 with equation

4x(x-5.07)+x=8.63
4x-20.28+x=8.63
5x=8.63+20.28
5x=28.91
x=5.782
18-4x=2x+3
2x+4x=18-3
6x=15
x=2.5
(2x-4)*3=(x+5)*4
6x-12=4x+20
6x-4x=12+20
2x=32
x=16