English translation I can't sleep the night before I take a big exam..Then I'm too tired to do well.What Should I do!

English translation I can't sleep the night before I take a big exam..Then I'm too tired to do well.What Should I do!

I can't sleep well the night before the exam. In that case, I will be too tired to do well in the exam. What should I do?

English translation
The sizes of MP3 players are very small,but small MP3 players make it easy to take hundreds of songs with you.
What do you mean by take, make and it
excuse me.

MP3 player size is very small, but you will be easier to store hundreds of songs in your MP3 player
Take means to store
Make it means "to succeed in doing something"

For a five digit number, the three digits on the left are five times the two digits on the right
Urgent, urgent~
Continue: the new five digit number is 75 times more than the original five digit number?

It turned out to be 12525
Suppose that the original two digit is x and the three digit is 5x
It turned out to be 5x * 100 + X
Now it's 1000 * x + 5 * X
The equation (5x * 100 + x) * 2 + 75 = 1000 * x + 5 * x is obtained
X=25
So
I don't have to

How to prove that the adjoint rank of matrix A is one (when R (a) = n – 1)

Firstly, by R (a) = n-1, there exists a non-zero subexpression of order n-1, so a * ≠ 0, R (a *) ≥ 1
Secondly, a is irreversible, a · a * = | a | · e = 0. There is R (a) + R (a *) - n ≤ R (a · a *) = 0, that is, R (a *) ≤ N-R (a) = 1
R (a *) = 1

The difference between 92.5 and X divided by 11 is 7.7. I'll wait

(92.5 - x)÷11 = 7.7
92.5 - x = 7.7×11
92.5 - x = 84.7
x = 92.5 - 84.7
x = 7.8

The first question about approximate number and significant number is not difficult!
69 (accurate to individual position) ≈_____ The significant numbers are_______ The significant number in this question refers to the first number or approximately equal to the last number!
What is the accuracy of 24000 and 13500?
Is approximate number 13.2 accurate to 100 million bits
If 1L is not correct, 24000 and 135000 must be converted to the number with 0
2.369 keep 3 significant numbers! (scientific counting)

69 (accurate to individual position) ≈_ 38____ The significant numbers are_____ 2
A significant number is a number that is approximately equal to the following number
24000 and 13500 are accurate to tens, respectively

A story book has 420 pages in total. Zhang Hua read one fourth of the whole book on the first day and three seventh of the whole book on the second day. How many fewer pages did he read on the first day than on the second day

420*（7/3)-420*(4/1)=30

Set a = {x | x ^ 2 - (a + 1) ^ 2x + 2A ^ 3 + 2A

A={x|(x-2a)[x-(a^2+1)]=1
iii)a^2+10

When the two cars meet, the distance of the bus is 30% more than that of the truck. After the two cars meet, they continue to move forward at the same speed. When the bus reaches B, the distance of the bus is 30 km more than that of the truck. How many kilometers are there between a and B?

The speed ratio of passenger and freight cars is: (1 + 30%): 1 = 13:10, the distance between a and B is 30 △ 13-10 × (13 + 10), = 30 △ 3 × 23, = 230 km. A: the distance between a and B is 230 km

B1 = 2, BN + 1 (subscript) = BN + 3N + 2, find {BN} general term formula

bn＋1-bn＝3n＋2
.
b2-b1=3+2
Add these n terms
We obtain BN + 1 = B1 + 2 * n + 3 * n (n + 1) / 2 = 2 (1 + n) + 3 * n (n + 1) / 2 = (n + 1) (2 + 3N / 2) = (n + 1) (3N + 4) / 2