How many days are there in 2001 and 2008? How many days are there in February?

How many days are there in 2001 and 2008? How many days are there in February?

365 days, 366 days, 2829

A column of numbers 3, 6, 8, 8, 4, 2... From the third number, each number is a digit of the product of the first two numbers, which is the number of 2008 in this column

The sequence is
3、6、8、8、4、2、8、
6、8、8、4、2、8……
Six in a cycle
With 2008 △ 6 = 334, more than 4
So it's going to be the third term of a cycle (because it starts from the second term)
That is, item 2008 is 8

A column of numbers: 3, 6, 8, 4, 2. From the third number, each number is a digit of the product of the first two numbers, then the number in this column is the number in 2008

"Invisible wings of love" Hello, I'm glad to answer for you!
Find the law. The sequence is
3、6、8、8、4、2、8、6、8、8、4、2、8……
If we exclude 3, we can see that there are 6 cycles
Then (2008-1) △ 6 = 334 3,
So it's the third term of a cycle,
Correspondingly, the number of 2008 is 8

An equation that contains only unknowns and the degree of unknowns is degree is called one variable one degree equation
The equation that contains only unknowns and the degree of unknowns is times is called one variable one degree equation

An integral equation with only one unknowns and the degree of unknowns is once

3x - 2 = 7 has only one unknown number, and the degree of the unknown number is (), so it is a linear equation with one variable

1

Four unknowns, three equations,
a=20x
a=12x+6y
a=6y+18z

a=20x
0=12x-18z
x=a/20 z=a/30 y=(a-3a/5)6=a/15

Solving the equation of five unknowns
10a+6b+5c+2e=229
6a+2b+6c+6e=264
13a+11b+9c+2e=361
11a+9b+7c+4d+2e=339
8a+8b+5c+2d+e=244

This is the most troublesome system of Equations I've ever done
a = 4
b = 12
c = 15
d = 21
e = -1

Solving the equation of two unknowns
To solve this problem, 18x + 2x = 60,

18X+2X=60
(18+2)X=60
X=3

Two equations of unknowns
5x+4y=360

360 can be decomposed into the following multipliers: 2 1803 1204 905 726 608 459 4010 3612 3015 2418 20. Among the above numbers, one that can be divided by 5 and the other that can be divided by 4 is: 4 905 728 4510 3612 3015 24, so x and y are 18 11 189 22 96 33 6 respectively

What is the equation of two unknowns
Speed ～～～
Must be accurate!
Is it a quadratic equation of one variable? It needs to be explained
Online, etc
(two different unknowns, such as x.y)

Once is called a quadratic equation of two variables
Quadratic is called bivariate quadratic equation