I won t solve the problem, I call for help, I won t do thank you

Let's first calculate how many tons were burned in a previous day: 12 10+ tons.

So original: 15* tons.

Let's answer X question correctly and answer y question incorrectly.

Column equations: 5*x-3*y=76

x+y=20

Solution: x=17 y=3

Let oranges be x, bananas y, and apples z

Column equations: x+y+z=995

x=2*y+123

z+245=x

Solution: x= y= z=

Let A be x, and B be y

Column equations: x+y=2200

x=2*y+380

You can solve the answer to this question yourself!

In fact, you only need to think about these questions simply, and you can use the hypothetical method, which your teacher has taught, right?

I won't write about the unit. *is a multiplier sign.

One. Let it be burned a every day, a total of x

x-15a=12

Two. Answer x correctly and answer y incorrectly

5x-3y=76

x+y=20

Three. Tangerine X, Banana Y, Apple Z

x+y+z=995

x=2y+123

z=x-245

Four. A x, B y

x+y=2200

y-210)*2-380=x

1.Set the original daily burning x tons.

15x+12=15x+10( x= original tons burned per day.

This pile of coal turned out to have tons).

2.Let's say you answered the x question correctly and answered the wrong (20-x) question.

5x+(-3 (20 x))=76 The solution is x=17, (20-x)=3, 17 questions answered correctly, and 3 questions answered incorrectly.

3.Let the banana have x kilograms.

x+2(2x+123)-245=995 x=kilograms for bananas and kilograms for oranges.

Apples have kilograms.

4.Set up the original x kg of grain storage in warehouse B.

x+2x-380=2200-210 x=790 The original grain storage in warehouse B was 790 kilograms, and the original grain storage in warehouse A was 2200-790=1410 kilograms.

A pile of coal, after burning for 15 days, there are still 12 tons left, and then save tons every day, and burn it for another 10 days to burn this pile of coal, how many tons of this pile of coal is there?

12 10=t) (t).

The school held a competition, each person must answer 20 questions, each correct answer is worth 5 points, and the wrong answer is deducted 3 points, Xiaomin scored 76 points, how many answers did he answer correctly, how many answers did he answer wrong?

20*5=100 (points) 100-76=24 (points) The wrong questions are: 24 (5+3)=3 (points).

The questions are: 20-3=17 (Dao).

The three fruits weigh a total of 995 kg, the orange is 123 kg more than 2 times the size of the banana, the apple is 245 kg less than the orange, how much does each of the three fruits weigh?

Let oranges be x, bananas y, and apples z

Column equations: x+y+z=995

x=2*y+123

z+245=x

Solution: orange = banana = apple =

The unit is (kg).

A and B granaries have a total of 2,200 kg of grain, and after 210 kg is transported out of B silos, silo A is 380 kg less than 2 times that of silo B.

Design: A(x-210)*2-380, B x

x-210)*2-380+x=2200

2x-420-380+x=2200

3x-800=2200

3x=2200+800

x=3000/3

x=1000

That is: A is: (1000-210)*2-380=1200

That is: already: 1000

The unit is (kg).

1.Basis: 3 roosters and 2 hens cost 102 yuan, buy 2 roosters and 3 hens cost 108 yuan.

Conclusion: Buy 5 roosters and 5 hens for a total of 210 yuan.

So: buy 1 rooster and 1 hen for a total of 42 yuan, buy 2 roosters and 2 hens for a total of 84 yuan According to: 3 roosters and 2 hens cost 102 yuan, buy 2 roosters and 2 hens for a total of 84 yuan: a rooster 38 yuan (102-84).

According to: 108 yuan for 2 roosters and 3 hens, and 84 yuan for 2 roosters and 2 hens: 24 yuan (108-84) for a hen

2.According to: the number of male students is 4 times less than that of female students, 2 times; There are 8 more than 3 times the number of female students, and it can be concluded that 1 time of female students is 10 people.

Think of it this way: it's twice as bad, 8 more than 2 less, it needs to be added together).

For example: I am eight centimeters taller than one meter, and you are two centimeters shorter than one meter, how tall do you say we are?

Knowing the number of girls, do boys still use me?

1.Set the rooster x yuan and the hen y yuan.

3x+2y=102

2x+3y=108

The solution yields x=18 and y=24

2.Set up female classmates x people.

4x-2=3x+8

The solution is x=10

1.Solution: Set each rooster to be $ x and each hen to be $ y.

3x+2y=102

2x+3y=108

2.Solution: There are x female classmates.

4x-2=3x+8

I hope you can unravel the mystery and provide ideas for yourself.

5. A city shall collect a monthly gas fee according to the following regulations: the part of gas used by each household within 60 cubic meters.

a fee per cubic metre; Excess of 60 cubic metres will be charged at $ per cubic metre.

wang fang's family paid a total of 60 YUAN FOR GAS LAST MONTH , AND HER FAMILY USED MORE THAN CUBIC METERS OF GAS LAST MONTHThe process can be written like this.

Column equation (60-60

70 (cubic meters).

A: Wang Fang's family used 70 cubic meters of natural gas last month.

If the right-angled side is a right-angled isosceles of four decimeters, then two right-angled triangles are a square with a side length of 4 decimeters.

2 meters wide can be divided into 2 sides, 18 meters long can be divided into 18 sides, the total divided square is:

18, which are then divided into isosceles right triangles, that is, (18 pieces.

17 minutes.

Suppose a1 b2 c5 d10

A B together, it took 2 minutes, A came back, let C D go together, a total of 11 minutes, B came back and picked up A took 4 minutes. 2 + 11 + 4 = 17 minutes.

1. The colorless one is the middle, so it is inferred that the three cubes have a layer on the top and bottom, the left and right, that is, the volume is: 5 times 3 times 3, and the result is that I calculated it.

2. Let the difference be x, the subtraction is 3x, and the subtraction is y, and the system of equations: {y+3x+x=536

The y-3x=x equation will be solved.

3. The volume of the cuboid is 2100 cubic centimeters, the product of length and width is 210, and the two numbers are integers of 14, and the latter of 15 is counted by themselves.

4. First look at how many faces have been added, 125, that is: 14 horizontally, 14 vertically, the volume of the cube remains unchanged, that is, the edge length of the small cube: 1 125, and then the edge length of 5/1 meter of the three root numbers, the area of a surface is 1/25, a total of 2 28 125 surfaces have been added, and the area is calculated plus the original large cube area.

45536÷2=268

14 + 15 = 29 cm.

1 meter = 10 decimeters.

10 5 = 2 decimeters.

2 2 6 125 = 3000 cubic decimeters.

1.The volume of the cuboid without red is 1 1 3, and the volume of the original cuboid is 5 3 3 = 45 (cubic centimeters).

2.Let the difference be x, then the subtraction is 3x, and the subtraction is x+3x=4x4x+3x+x=536

Solution x=67

Hence the subtraction is.

3.Because 2100 = 10*210

210 = 2 * 3 * 5 * 7 = (2 * 7) * (3 * 5) = 14 * 15 Therefore, the sum of the length and width of the cuboid is 14 + 15 = 29 cm 4The edge length of a cube is 1 meter, and it is sawn into 125 small cubes of the same size, and the volume of a small cube is 1*1*1 125 = cubic meters.

So, the edge length of a small cube is meters.

The sum of the surface area of these small cubes is square meters.

(1) The volume of the original cuboid is: (3 + 2) * (1 + 2) * (1 + 2) = 5 * 3 * 3 = 45 cubic centimeters.

2) Let the subtracted number, subtracted number, and difference be a, b, and c respectively; Then there is the equation:

a+b+c=536；b=3c；a-b=c；

Solution: a=268, b=201, c=67;

So the minus is 201.

3) Set the length and width of a centimeter and b centimeter respectively (a and b are positive integers).

a*b=210，a>10,b>10；

Solution: a=14, b=15 or a=15, b=14.

4) Solution 1:

5*5*5=125, so, 5*2*3=30 square meters Solution 2:

As can be seen from the question, if there are five small cubes on each edge, then the edge length of each small cube is meters, and the surface area of a single cube is: Square metre.