It is known that the lengths of the two sides of the triangle are 3 and 2 respectively, and the value of the third side is the root of the quadratic equation x ^ 2-x-6 = 0, so the perimeter of the triangle can be obtained

It is known that the lengths of the two sides of the triangle are 3 and 2 respectively, and the value of the third side is the root of the quadratic equation x ^ 2-x-6 = 0, so the perimeter of the triangle can be obtained

x²-x-6=0
（x-3）（x+2）=0
Solution
X1 = 3, X2 = - 2, rounding off
The third side is three
So the perimeter is:
3+3+2=8

A group of students go to the park to play, male students are wearing blue sports cap, female students are wearing red sports cap, one of the male students said: "I see the number of blue sports cap and red sports cap is equal". A female student said: "in my opinion, the number of blue sports cap is the square of the number of red sports cap". How many male students, how many female students?

Suppose there are x female students and (x + 1) male students in this group. According to the meaning of the question, we get: (x-1) 2 = x + 1, and the solution is: X1 = 3, X2 = 0. When X1 = 3, x + 1 = 4. A: there are 4 male students and 3 female students in this group

Grade 6 Volume 1 Chinese unit 4 cartoon composition 400 words

I read such a cartoon in a comic book: in a big forest, a man with a cigarette in his mouth and a sharp axe cut down big trees, and the trees were crying. A woodpecker stopped on the man's shoulder. The woodpecker looked at the man's head and said, "there must be insects in this section of wood." no

There are 3000 chickens in a farm, and the ducks are three fifths of the chickens. How many ducks?

3000x (3 / 5) = 600x3 = 1800

57 to the power of 2015

The one digit number of 57 is: 7
The second power of 57 is 9
The number to the third power of 57 is 3
The fourth power of 57 is 1
The number to the fifth power of 57 is 7
.
The n-th power number of 57 is about 7,9,3,1 cycles
2015/4=503.3
So the 2015 power of 57 is 1

If the line segment a ＞ B ＞ C is known, the condition that it can form a triangle is ()
A. a=b+cB. a+c＞bC. b+c＜aD. a-b＜c

∵ a ＞ B ＞ C, according to the trilateral relationship of the triangle, it can be concluded that the condition to form a triangle is B + C ＞ a, and the deformation is A-B ＜ C, so D

The sequence {n-1 power of 3} is grouped according to the rule of the nth group of N numbers, as follows (1) (3,9) (27,81243)···
Then the first number of the 100th group is

3^[(1+99)99/2]=3^4950

In the expansion of (x-1 / 2x) 7, the binomial coefficient with x ^ 3 is

21/4

The application of the first degree equation of one variable in junior high school mathematics
1. The price of a commodity is increased by 30% according to the cost price, and then it is sold at a 20% discount. The price is 208 yuan. How much is the cost price of this commodity?
2. A harvester team completes the first 12 hectares of wheat every day. After finishing 2 / 3 of the first wheat field, the team improves its operation. The efficiency is increased to 5 / 4 of the original, so it is completed one day earlier than the scheduled time?
3. List a practical problem in the actual situation, and ask to use the equation (1-25%) x = 112

Suppose the original price is x yuan. (1 + 30%) x × 0.8 = 2081.3 × 0.8x = 2081.04x = 208x = 200 answer: the cost price is 200 yuan. Suppose the scheduled time is x days. 12x = 12 * (4 / 5) (x-1) 12x = 15 (x-1) 12x = 15x-1512x-15x = - 15-3x = - 15x = 512 * 5 = 60 (HA). Answer: this wheat field has 60 ha. (3) the original price of a commodity is

What is the remainder of Formula 1! + 2! + 3! +... + 2013! Divided by 100?

First of all, 100 = 10 * 2 * 5, because all greater than 10! Can be decomposed into 10 * 5 * 2 * (x), so the remainder of the sum of these numbers is 0. Then this formula becomes the formula 1! + 2! + 3! +... + 9! Divide the remainder of 100 to find the remainder (1 + 2 + 6 + 24 + 120 + 720 + 5040 + 40320 + 362880) / 100. Because it is a ball remainder, it is greater than