Mr. Wang wants to buy 24 fairy tales. The unit price of each fairy tale in the two bookstores is 10 yuan. The original price of bookstore a is 10% lower than that of bookstore B. If you buy five, you can get one free. If you don't get five, please figure out which bookstore Mr. Wang goes to to buy books cheaper

Mr. Wang wants to buy 24 fairy tales. The unit price of each fairy tale in the two bookstores is 10 yuan. The original price of bookstore a is 10% lower than that of bookstore B. If you buy five, you can get one free. If you don't get five, please figure out which bookstore Mr. Wang goes to to buy books cheaper

If you go to a bookstore, you need: 24 × 10 × 90% = 216 yuan
If you go to Bookstore B, you need to buy 5 for 1 free, so Mr. Wang only needs to pay 20 books for 24 story books, that is, 20 × 10 = 200 yuan
So it's cheaper to go to bookstore B

A total of 12 copies of fairy tales, each at the same price, are 4.8 yuan, activities, a bookstore to buy three free one, B bookstore to buy a set of 20%
Which one is suitable? (how much is bookstore a? How much is Bookstore B?

12 × 4.8 × 0.8 = 46.08
4.8 × 9 = 43.2 a
A: 43.2 yuan for shop a and 46.08 yuan for shop B. buy shop a

From place a to place B, it takes 8 hours for buses and 10 hours for trucks. The speed of buses is faster than that of trucks ()
A. 20%B. 25%C. 125%D. 120%

(18-110) △ 110 = 140 △ 110, = 25%. A: the speed of passenger cars is 25% faster than that of freight cars

In the sequence {an}, A1 = 2, a (n + 1) = a (n) + 2n. (1) find the general term formula of {an}. (2) if a (n) + 3n-2 = 2 / b (n), find the first n terms and s of the sequence {BN}
In the sequence {an}, A1 = 2, a (n + 1) = a (n) + 2n. (1) find the general term formula of {an}. (2) if a (n) + 3n-2 = 2 / b (n), find the first n terms and S (n) of the sequence {BN}

a(n+1)=an+2nan - a(n-1)=2(n-1)an - a1 = 2( 1+2+...+(n-1))= n(n-1)an = n^2-n+2an+2n-2 = 2/bnbn = 2/(an+2n-2)=2/(n^2+n)= 2[ 1/n -1/(n+1) ]Sn = b1+b2+...+bn=2( 1- 1/(n+1) ]= 2n/(n+1)

1: There are nine numbers. Their average is 72. After one number is removed, the average is 78. What is the number removed?
2: Xiao Hong's family has an alarm clock, which strikes twice an hour, several days at a few points, and once in half an hour. How many times does the alarm clock strike from 0:00 to 12:00
3: There is an alarm clock that is three minutes fast in a day and night. Xiaohua has to catch the train. If she wants to make the alarm clock go on time at 8:00 Beijing time tomorrow morning, how many minutes should she slow down when the alarm clock goes to 4:00 p.m?

The sum of nine numbers is 9 * 72 = 648, after one number is removed, it becomes eight numbers. The sum of nine numbers is 8 * 78 = 624, after one number is removed, the number is 648-624 = 24. The sum of the second question in half an hour is: there is a total of 0.30-11.30 in half an hour, and the number of knocks is 123.12 in half an hour

① An integral equation with () unknowns and the degree of the unknowns is () is called bivariate linear equation
② A system of binary linear equations is formed by combining () binary linear equations with the same unknowns
③ The solution of binary linear equations: (1)___ （2）___ .
④ There are innumerable solutions to the quadratic equation x-2y = 1. Among the following four sets of values, the one that is not the solution of the equation is ()
a. {x = 0, y = minus 1 / 2}
b.{x=1,y=1
c.{x=1,y=0
d.{x=-1,y=-1
⑤ The solution of the system {X-Y = 2,2x + y = 4} is___ .
⑥ To solve the equations: (1) {x + 2Y = 1,3x-2y = 11 (2) {a + B + C = 0,4a + 2B + C = 4, C = - 2)

One two one
Two or two
Three substitution method and elimination method
IV B
Five x = 2 y = 0
Six x = 3 y = - 1 a = 1 b = 1

Does a spaceship fly from the earth to the moon and from the moon to the earth, using the same fuel? Which one is more?

Fuel consumption is certainly different
The gravity of the earth is relatively large, so it takes more power to break away

X minus 25X equals 27,

x - 25%x = 27
75%x = 27
x = 27÷75%
x=36

Prizing off the bottle cap, principle pressure, pressure, friction force?
It's not the bottle opener that knocks the bottle cap, it's the relationship between the bottle cap and the bottle

The principle of prying open the bottle cap is mainly the lever principle

If 10 -If 2x = 25, then 10 What is x equal to
One fifth of a, one-fifth of B, one-fifth of C, one-fifth of D, one-fifth of C, one-fifth of a, one-fifth of B, one-fifth of C, one-fifth of D,

10 ^ - 2x = 25, find 10 ^ x? 25 ^ - 2 = one fifth, so choose a, one fifth