Those who know math are good plus

This is junior high school.

Real numbers are divided into rational numbers and irrational numbers. Rational numbers are regular numbers, like 2's.

Irrational numbers are irregular numbers, such as some numbers like this.

0 is not a rational number or an irrational number.

Just understand a little, mathematics is mainly for understanding + practice, don't memorize.

Master the difference between rational and irrational numbers. Rational numbers can be expressed as decimal or fractions, and specific hopes can be given a few questions** I don't understand, and you can have targeted guidance.

Solution: One

by 2x -5x+a 0

It can be obtained, x1 = (5 - root number (25-8a)) 4x2 = (5 + root number (25-8a)) 4

x1 × x2=a/2

In this step, you can actually just use Vedic theorem x1 x2=c a=a 2 a 2 2=1 4

a=1 Second, substitute a=1 into and

According to the Pythagorean theorem, get hypotenuse = (root number 21) 2

It's a very simple problem, it's supposed to be a function problem, but I'm not good at math.

Let m and n be two.

25-8a≥0

a≤25/8

According to Veda's theorem.

m+n=5/2

m*n=a/2

Triangle Area:

1/2*mn=a/4=1/4

a=1m*n=1/2

Let the hypotenuse length be k

k^2=m^2+n^2

m+n)^2-2mn

The hypotenuse is 21 2 long

Let the root be x1, x2, and the triangle area = x1*x2 2=1 4, so x1*x2=1 2

By the Vedic theorem.

x1*x2=a/2

So a = 1 generation of equations, solved by the formula:

x1 = (5 + root number 17) 4

x2 = (5 + root number 17) 4

So the hypotenuse length is:

x1 2 + x2 2 open the root number again and get it.

Root No. 21) 2

2a-1|0 and |5b-4|=0, a 1 2, b 4 5, and you're done.

x+3) and |y-2|They are all non-negative numbers, so if they want to be the opposite of each other, they must be zero, so that we can get x 3, y 2, and the rational number with the smallest absolute value is 0, so z 0, and the rest should be.

1/4 x (4) 1

10) x 1/10 1

2/9 x (9/2) 1

15/10) x 10/15 1

1/2 x (2) 1

10）x0．1＝1

Quarter * 4 = 1

10 * 1/10 = 1

Two-ninths * nine-two-in-half = 1

Three-two-thirds * ten-fifteenths = 1

One-half * 2 = 110 *

Your formula is written in a way that is not very incomprehensible, 1/4x( )1,( x1/10 1. Or are they a big equation, 1 2/9 ( ) is 1 and 2/9 ( ) or whatever.

1. If the length of the three sides of a triangle is , x, then the value range of x is

2. If the three sides of a triangle are known to be 3 and a, then the value range of a is

3. The length of one side of the isosceles triangle is 5, and the length of the other side is 8, then its circumference is

4. The length of one side of the isosceles triangle is 3, and the length of the other side is 8, then its circumference is

5. The length of both sides of a triangle is , then the range of its circumference c is

Answer: OR 21

Wouldn't it be OK to change the number?

Then use the triangle theorem to test, discard the non-conforming...

7-5=2 7+5=12 So 2<3-2a<12 simplify: 2<3-2a is 2a<1 is a<1 2

3-2a<12 is -2a<9 is -1 4, so the answer is 0

0 But since one side is unknown, the case of a should be classified and discussed to determine which two are the shortest side.

Let the ten-digit number be x, then the single digit is x+310(x+3)+x=2(10x+x+3)+2 to get x=2

A: This two-digit number is 25

25 solution: Let the original number be 10a+b

then b-a=3

10b+a=2*(10a+b)+2

Solve the equation to get a=2b=5

Set the single digit x and the ten digit y

x-y=3, (10x+y)-2=(10y+x)*2, just solve the equation by yourself to find x y

Let the original two-digit number be xy, and x be the number in the ten digit, then there is.

y-x=3y*10+x=2(x*10+y）+2

Find x=2 y=5

The original two-digit number was 25

201 are all x*10+1 (x1 is an integer from 1 to 201) and take oranges.

The general formula for the previous comma is an=2n-1, and the general formula for the latter is bn=5n+1

The first one can be written as 2n+1, and the second can be written as 5m+1, and its common multiple is 10k+1

10k+1<=2011, you can find k=201, because k cannot take zero, and the trained manuscript takes k as the age of all the whole bands from 1 to 201.

A total of 201.

1,3,5,7,9.。。2011 is all the odd numbers from 1 to 2011, and the number that appears in these two columns at the same time is to know that Li Gai 6, 11, 16, 21... For the number of odd numbers in 2011, add 10 each time from 11 to get the next odd number, that is, 11+10n=2011

The solution is n=200, plus 11, and there are 201 judgments.

The first one is the same number as eleven, and the two series are the equal difference series of 2 and 5 before the tolerance, so every ten is added to the total number of a male split. (2011-11)/10