In order to strengthen the flood control work, the municipal engineering team is preparing to reinforce a 2240 meter long embankment of Suzhou River. Due to the new reinforcement mode, the length of reinforcement planned every day is increased by 20 meters compared with the original plan. Therefore, the number of days required to complete the reinforcement project will be shortened by 2 days compared with the original plan. In order to further shorten the time of reinforcement project, if 224 meters are required to be reinforced every day, then On the basis of the present plan, how many meters will be added to the length of reinforcement every day?

Let's suppose the length of reinforcement x meters per day in the original plan. From the meaning of the question, we can get: 2240 x − 2240 x + 20 = 2. The solution is: x = 140 or x = - 160. (not suitable for the question) after the test, x = 140 is the solution of the original equation. If it is required to reinforce 224 meters per day, then on the basis of the present plan, the length of reinforcement will be increased by 224-140-20 = 64 meters per day

Applied problems of quadratic equations of one variable
Xiao Wang bought vegetables in the vegetable market. Three eggs for 1 yuan. One duck egg for 3 yuan. One goose egg for 7 yuan. Xiao Wang bought 100 eggs for 100 yuan. How many eggs did he buy, duck eggs and hungry eggs?

Egg 78, duck egg 20, hungry egg 2,
Egg 81, duck 15, hungry 4
Eggs 84, duck eggs 10, hungry eggs 6
Egg 87, duck 5, hungry 8
Egg 90, duck egg 0, hungry egg 10
Egg 75, duck egg 25, hungry egg 0

The turnover of a store in February was 500000 yuan, which decreased by 30% in March after the Spring Festival. The growth rate in April was 5% higher than that in April, and the turnover reached 483000 yuan

Suppose the growth rate in April is x, then the growth rate in May is (x + 5%). According to the meaning of the question, we get: 50 (1-30%) (1 + x) (1 + X + 5%) = 48.3, 35 [(1 + x) 2 + 5% (1 + x)] = 48.3, (1 + x) 2 + 5% (1 + x) - 1.38 = 0, (1 + x-1.15) (1 + X + 1.2) = 0, (x-0.15) (2.2 + x) = 0, that is, x-0.15 = 0 or 2.2 + x = 0, we get: x = 15% or x = - 2.2 A: the percentage increases in April and may are 15% and 20% respectively

Solving practical problems with quadratic equation of one variable
1. The company paid 10000 yuan to the state in January and 12544 yuan in March. What is the average growth rate of the company's tax payment in these two months?
2. The deposit amount of a savings office in January this year was 6 million yuan, which decreased by 10% in February. Since March, the propaganda has been strengthened, and the deposit amount has increased steadily. By April, the deposit amount has reached 6.534 million yuan, which is the average growth rate in March and April
Come on, who's in a hurry~~~~~

1. Let the average growth rate be X
10000(1+x)(1+x)=12544
x=1.12
2. Let the average growth rate of March and April be X
600(1-10%)(1+X)(1+X)=653.4
X=10%
(1 + x) (1 + x) means the square of (1 + x)
I don't know how to express it
I'm sorry

Glue naming problem! How to define, such as 502 503

Your 502503 is just two common models of super glue. The naming is based on the type of group in the main components of glue. For example, methyl ester is 1, named 501; ethyl ester is 2, named 502; propyl ester is 3, named 503, and so on

If you cut a 10 decimeter long log by 3 decimeters, the surface area will increase by 12.56 square decimeters. What is the volume of the remaining cylinder

The surface area is increased by two bottom areas
What is the base area of the cylinder
12.56 △ 2 = 6.28 (square decimeter)
The rest of the cylinder is long
10-3 = 7 (decimeter)
What is the volume of the remaining cylinder
6.28 × 7 = 43.96 (cubic decimeter)

The equation is solved. (1) 1.69 / (X-2) = 1.3 (2). X: 9 / 7 = 14:3.6 (3). 1 / (x + 2 / 3) = 4 / 5
The answer is correct!

（1）1.69/（X-2）=1.3
1.3/(x-2)=1
1.3=x-2
x=3.3
（2）.X：9/7=14:3.6
x*3.6=14*9/7
x*3.6=18
x=5
（3）.1/（X+2/3）=4/5
4*(x+2/3)=5
4x+8/3=5
4x=7/3
x=7/12

Parallelogram with equal base and height has larger area than triangle______ %．

The area ratio of a parallelogram with equal base and height to a triangle is: ah: 12Ah = 2:1; the area of a parallelogram with equal base and height is larger than that of a triangle: (2-1) △ 1 = 100%; so the answer is: 100

(1/2013-1)（1/2012-1)(1/2011-1)… （1/3-1)(1/2-1）=

(1/2013-1)（1/2012-1)(1/2011-1)… (1 / 3-1) (1 / 2-1) total 2012 groups
=（-2012/2013）×（-2011/2012）×…… ×（-2/3）×（-1/2）
The number of negative factors is even, so the product is positive
The numerator and denominator of adjacent numbers can be reduced, leaving the denominator of the first number and the numerator of the last number
=1/2013

In the triangle ABC, ad is perpendicular to BC and D, ad = BC = a, AC = B, ab = C, then what is the maximum value of B / C + C / b?

Five roots
Using the triangle area formula s = 0.5 * Sina * BC, s = 0.5A (square) and cosine theorem, we can get an expression about B / C + C / B, which is equal to several times of sina + several times of cosa, and then transform it into the trigonometric function value of an angle. Using the value range of a, we can find that the maximum value obtained is root 5

Applied problems of quadratic equations of one variable Xiao Wang bought vegetables in the vegetable market. Three eggs for 1 yuan. One duck egg for 3 yuan. One goose egg for 7 yuan. Xiao Wang bought 100 eggs for 100 yuan. How many eggs did he buy, duck eggs and hungry eggs?