Team a, team B and team C built a highway. Team a built three eighths of the total length. Team B built 40 meters more than team C. how long is the road? Xiaoxing, Xiaohong and Xiaohua have 207 shells in total. Xiaoxing takes 5, Xiaohong takes 4, Xiaohong takes 5, and Xiaohua takes 6. When all the shells are taken, how many shells will each of the three take?

Team a, team B and team C built a highway. Team a built three eighths of the total length. Team B built 40 meters more than team C. how long is the road? Xiaoxing, Xiaohong and Xiaohua have 207 shells in total. Xiaoxing takes 5, Xiaohong takes 4, Xiaohong takes 5, and Xiaohua takes 6. When all the shells are taken, how many shells will each of the three take?

2) When Xiaoxing takes 25, Xiaohong takes 20, Xiaohua takes 24, totally 69, 207 / 69 = 3, so Xiaohong takes 20 * 3 = 60; Xiaohua 24 * 3 = 72, Xiaoxing 25 * 3 = 75
Is the first question short of conditions

｛2a+2b= — 1 ｛4a — 9b=8 Is this equation set swollen?

2a+2b=-1 ①
4a-9b=8 ②
①*2 4a+4b=-2 ③
②-③ 13b=6
b==-10/13
Put B = - 10 / 13 into the equation a = 4 / 5

1. Find the nonnegative integer solution of 3x + y = 10? 2. Given the bivariate equation 3x + 2Y = 7, if y is expressed by the formula containing x, then y=______ . 3. It is known that the bivariate linear equation 2x + 3Y + 5 = 0 (1) The known equation is written as the algebraic expression of y to express X; Find the complete solutions to these questions

x=1,y=7
x=2,y=4
x=3,y=1
y=7/2-x*3/2
y=-x2/3-5/3

There is a group of sheep. Some of them go up the mountain, and the other part is still at the bottom of the mountain. If there are three sheep at the bottom of the mountain, the sheep at the bottom of the mountain account for one third of the whole sheep. If there are three sheep down from the mountain, there will be as many sheep at the foot of the mountain. Do you know how many sheep there are on the mountain and at the bottom of the mountain? I want to see how it's written,

Let X be the ascending one and y the downhill one
y-3=1/3(x+y)
y+3=x-3
The solution is x = 21, y = 15

Solution of fractional equation in eighth grade mathematics

The most simple common denominator is to convert the fractional equation into an integral equation; ② to find the value of the unknown according to the steps of solving the integral equation (transfer the term, merge the similar terms, and change the coefficient to 1); ③ root test (after the value of the unknown number is obtained, the root must be tested, because in the process of converting the fractional equation into an integral equation, the range of the unknown number is enlarged, which may produce

Xiaoming and Xiaoliang do addition games. Xiaoming writes an extra 0 after one addend, and the sum is 242; while Xiaoliang writes an extra 0 after another addend, and the sum is 341. What are the original two addends?

Let one addend be x and the other y
According to the meaning of the title
10x+y＝242
x+10y＝341
The solution
x＝21
y＝32 ．
A: the two addends were 21 and 32

Bivariate linear equation When a shopping mall sells a certain commodity according to its price, it can make a profit of 45 yuan per piece; if it sells 8 pieces of the commodity at a discount of 15% of the price, the profit is equal to that of selling 12 pieces of the commodity by reducing the price by 35 yuan?

Suppose the purchase price is X Yuan and the price is y yuan
According to "a shopping mall can make a profit of 45 yuan when selling goods at a fixed price"
y－x＝45 ………… （1）
"8 pieces of this item are sold at a 15% discount on the price" is
8×（0.85×y－x）
"Reduce 35 yuan and sell 12 pieces of this item"
12×（(y－35)－x）
"The profit of selling 8 pieces of this article at a 15% discount of the price is the same as that of selling 12 pieces of this article after reducing the price by 35 yuan"
8×（0.85×y－x）＝12×（(y－35)－x）…… （2）
According to (1) and (2), the solution is as follows:
Price x = 155 yuan, price y = 200 yuan

The substitution method of the solution of the first degree binary equation in junior high school 3x+7y=5 4x+6y=0 To get it right, Use the substitution method!

From the first equation we know that x = 5 / 3-7y / 3, take the second equation, 20 / 3-10y / 3 = 0, we get y = 2, x = - 3

The first mathematics of junior high school There are 40 students in a class who go to a performance and buy tickets of type A and B for 370 yuan, including 10 yuan for a ticket and 8 yuan for B ticket. X tickets for type A and Y tickets for type B can be set up-------------- In the equation 3x + 2Y = 12, y is expressed by the formula containing x, and the corresponding Y values are obtained by assuming x = 2,3,4,5

1. The equation system is: x + y = 40,10x + 4Y = 370, the solution is x = 35, y = 5
2.3x + 2Y = 12, then 2Y = 12-3x, that is, y = 6-1.5x, when x = 2, y = 6-3 = 3, when x = 3, y = 6-4.5 = 1.5, when x = 4, y = 6-6 = 0, when x = 5, y = 6-7.5 = - 1.5

On the problems of bivariate first degree equation in junior high school （1）｛y=x+3 （2）｛3s-t=5 7x+5y=9 5s+2t=15 （3）｛3x+4y=16 （4）｛4（x-y-1）=3（1-y）-2 5x-6y = 33 half x + y = 2 The detailed solution process is required Application question: 4. A class goes to see a performance, each ticket of type A is 24 yuan, and that of type B is 18 yuan. If 35 students just spent 750 yuan on tickets, how many tickets have been bought for each? 5. Shunfeng Travel Agency organized 200 people to visit huaguoling and Yunshui cave. The number of tourists to huaguoling is twice as much as that to Yunshui cave, one less person. What are the number of tourists to the two places? The detailed process is required thank you.

1.｛y=x+3 ①
7x+5y=9 ②
Substituting (1) into (2) yields:
7x+5（x+3)=9
7x+5x+15=9
12x=-6
x=-2
By substituting x = 2 into ①, we get the following result:
y=-2+3
Y=1
So: {x = - 2 is the solution of the equation
Y=1
2.｛3s-t=5 ①
5s+2t=15 ②
According to the results of (1)
3s-5=t ③
Replace 3 with 2
5s+2(3s-5)=15
5s+6s-10=15
11s=25
s=25\11
By substituting s = 25 / 11 into (2), we get the following results:
t=20、\11
So the equation is 25
t=20\11
3.3｛x+4y=16 ①
5x-6y=33 ②
From (1)
4y-16=-x
16-4y=x ③
Replace 3 with 2
5（16-4y）-6y=33
80-20y-6y=33
y=47\26
Substituting y = 47 / 26 into (1)
x=114\13
Therefore, the solution of the equations is {x = 114-13
y=47\26
4.｛4（x-y-1）=3（1-y）-2 ①
Half x + y = 2
From ①, 4x-4y-4 = 3-3y-2
4x-y=5 ③
② * 3 + 3
3\2x+4x=11
x=1\2
Put x = 1 / 2 into (3)
y=-3
Therefore, the solution of this set of equations is {x = 1.2
y=-3
4. Buy x tickets for type A and Y tickets for type B
{24x+18y=750 ①
x+y=35 ②
From (2)
35-x=y ③
Put 3 into 1
24x+18（35-x）=750
（24-18）x=120
x=20
Substituting x = 20 in (2)
y=15
test
A:————————
5. X people to huaguoling and y to Yunshui cave
{x+y=200 ①
2y-1=x ②
It is obtained by substituting (2) into (1)
2y-1+y=200
y=67
Substituting y = 67 into (1)
x=133
test
A:————————