He said I am better at reading

He said I am better at reading

He said that I was better at reading .

There are so many books on your bookshelf

There are many(a lot of)books on your bookshelf!

A bookshelf full of books

bookshelf full of books

The prime numbers in the five digit number 54321 can be obtained by arbitrarily changing the position of each digit of the five digit number 54321___ ．

Because the characteristic of divisible by 3 is that the sum of the numbers on each bit can be divisible by 3, this number can be divisible by 3. Because 1 + 2 + 3 + 4 + 5 = 1515 can be divisible by 3, any number from 54321 can be divisible by 3

The solution set of inequality 4x-1 > 2x is

4x-1>2x
2x>1
x>1/2
The solution set is {x │ x > 1 / 2}

1. Given that P is on the straight line AB, and | AP | = 1 / 2 | Pb |, and a (0,1) B (- 1,2), find the coordinates of point P
2. Given a (1,2) B (3,2) a = (x + 3, x-3y-4) if a = AB, find the value of real number x.y

1. Because | AP | = 1 / 2 | Pb|
So | AP | = 1 / 3 | ab|
So the abscissa of point P is: (- 1-0) / 3 = - 1 / 3
The ordinate of point P is: (2-1) / 3 + 1 = 4 / 3
So p (- 1 / 3,4 / 3)
2.AB=（3-1,2-2）=（2,0）
So x + 3 = 2
x-3y-4
So x = - 1, y = - 5 / 3

How to find the coordinates of the center of gravity of a triangle?

If a (x1, Y1) B (X2, Y2) C (X3, Y3) is set in the triangle ABC, then the center of gravity coordinates are (x1 + x2 + X3 / 3, Y1 + Y2 + Y3 / 3)

For the quadratic trinomial x2-10x + 36, Xiao Cong made the following conclusion: no matter what real number x takes, its value can't be equal to 11. Do you agree with him? Explain your reasons

Method 1: when x2-10x + 36 = 11; x2-10x + 25 = 0; (X-5) 2 = 0, X1 = x2 = 5. Method 2: disagree. ∵ x2-10x + 36 = (X-5) 2 + 11; when x = 5, x2-10x + 36 = (X-5) 2 + 11 = 11

DF (x) = f (x) DX / / what do DF and DX mean respectively?

D means differential

(1) For n-dimensional vector group A: a (1), a (2), a (3). A (m), what is the definition of linear correlation? What are the methods to distinguish correlation from uncorrelation
Give two examples
(2) How to define the maximal linearly independent group of vector group A: A1, A2, ··· am? What is its significance?
(3) Specifically, whether the following vector groups are linearly correlated?
A1 = (- 131) t, A2 = (210) t, A3 = (141) t

(1) Definition: if there is a group of numbers which are not all zero such that k1a1 +... + KSAs = 0, then the vector group A1,..., as is said to be linearly correlated
The discriminant method is as follows
A 1,..., as is linearly related if and only if the homogeneous linear equations (a 1,..., as) x = 0 have nonzero solutions
A 1,..., as is linearly correlated if and only if R (a 1,..., as)