Before the summer vacation, students go to the library to borrow books. If each of them borrows 4 books, they will lose 2 books in the end. If each of the first 2 people borrows 8 books first, and each of the remaining people borrows 3 books, what is the total number of books?

Before the summer vacation, students go to the library to borrow books. If each of them borrows 4 books, they will lose 2 books in the end. If each of the first 2 people borrows 8 books first, and each of the remaining people borrows 3 books, what is the total number of books?

In the second borrowing method, if each person borrows 3 books, the rest: (8-3) × 2 = 10 (Books); the difference between the two borrowing methods: 4-3 = 1 (Books); the difference between the two borrowing methods: 10 + 2 = 12 (Books); the total number of books borrowed: 12 △ 1 = 12 (people); the total number of books: 4 × 12-2 = 46 (Books). A: the total number of books is 46

There are four kinds of books in the school library: A, B, C and D. It is stipulated that each student can pick up two books at most. Among the 95 students who borrow books, they can guarantee at least two books
How many people have the same number type

There are four types of C (4,1) = for borrowing only one book, and six types of C (4,2) = for borrowing two books,
Available: there are 4 + 6 = 10 types of books borrowed;
Because, 95 △ 10 = 9 5 ,
Therefore, we can guarantee that at least 9 + 1 = 10 people borrow exactly the same type of books

Notes for Library

No smoking

Grandma went to the supermarket to buy 4 bottles of coke and 7 barrels of milk, sharing 63 yuan. Each bottle of coke is 3.5 yuan, and the milk is 1 barrel
The answer to a series of equations

7x+4×3.5=63
x=7

-2 & #178; + 2 to the zeroth power - | - 3 × (- 3) to the minus first power

-2² + 2^0 - |-3| ×（-3）^(-1)
= -4 + 1 - 3 × （-1/3）
= -3 + 1
= -2

The distance between the two places is 400 km. A truck starts from place a and goes to place B at 55 km per hour. One hour later, a bus stops at 60 km per hour
How many kilometers did the bus travel when they met? (OK, plus bonus points)

If the truck goes one hour first, it will go 55 × 1 = 55 km first
At this time, the distance between the two vehicles is 400-55 = 345 km
The two cars travel 55 + 60 = 115 km per hour
So when two cars meet, it takes 345 △ 115 = 3 hours
3-hour bus travel: 60 × 3 = 180 km
A: when the two cars met, the bus traveled 180 kilometers

Simple algorithm of 2005 * 2003 / 2004 + 1 / 2004 and 3 / 5 * 1 / 13 + 5 / 9 * 3 / 13 + 5 / 18 * 6 / 13

2005 * 2003 / 2004 + 1 / 2004 = [(2004 + 1) (2004-1) + 1] / 2004 = (2004 & # 178; - 1 + 1) / 2004 = 2004 & # 178 / / 2004 = 20045 / 3 * 1 / 13 + 5 / 9 * 3 / 13 + 5 / 18 * 6 / 13 = 5 / 3 × 1 / 13 + 5 / 3 × 1 / 13 + 5 / 3 × 1 / 13 = 5 / 3 × 1 / 13 / 13 = 5 / 3 × 3 = 5 / 13, so it's easy. It's really troublesome just now

The two cars start from two places at the same time and travel in opposite directions. Car a travels 80 kilometers per hour, car B 69 kilometers per hour, and the distance between the two cars is 25 kilometers three hours later
How many kilometers is the distance between the two places?

Three hours later, the two cars were 25 kilometers apart, indicating that they did not meet
The distance between the two places is (80 + 69) * 3 + 25 = 472km

If the solution x = y of the equations 2x + 3Y = 1 and (k-1) x + (K + 1) y = 4, then K is?

10

A and B start from a and B at the same time and run in opposite directions. The two vehicles meet 36 kilometers away from the destination. It is known that the speed ratio of a and B is 4:5. It is urgent to find the distance between a and B, the process and the formula~

Right
36÷【1/2-4/（4+5）】
=36÷【1/2-4/9】
=36÷1/18
=648 km