- ? Twelve steps from Tian Guang and fourteen steps from Tian Guang. Find field geometry? Answer: 168 step.

Square field refers to the area-you can understand it as calculating the area of the field.

Tian, 12 step width, from 14 step-rectangle, length 12, width 14.

Ask Tian geometry? -Geometry here refers to finding the area.

A: Step 168. -The area is 168, and the area unit has no concept of square. Step by step, or step.

Next question ~

-Today, there are * * * to buy a dog, and people pay five, less than ninety; Fifty is enough. Ask the number of people, the dog price geometry.

-Answer: The price of a dog for two people is 100.

-Surplus, sufficient, insufficient and sufficient operations: according to the number of surplus and shortage. Set the rate, use less and reduce more, and the rest is the law. It is as good as the law. The person who asks the price will get the price according to the number of people.

The second question is not a word, I will translate it directly into modern language for you:

The problem is: buy a dog, everyone goes out of 5 yuan and goes to 90 yuan; Everyone out of 50 yuan, just right. How many people want to buy dogs?

(Note here that the question does not ask how many dogs there are, nor does it ask the unit price of dogs. Dogs are a whole here, but how much does it cost to buy a dog? )

The answer is: the total price of two people and dogs 100 yuan.

Answer analysis, here is the most troublesome:

Surplus refers to how much everyone pays. The surplus is adequate and just right.

What about the shortage? According to the sufficient technique, the sufficient technique is the surplus and deficiency technique mentioned in the previous chapters of the Nine Chapters Calculation Classic.

The quantity of surplus and shortage is real. Set the rate, use less and reduce more, and the rest is the law.

The difference in income is real, and the calculation rate is: the more you use, the less, and the more you exceed.

What's the difference in profit (how much each person pays)? 50-5=45 ? This 45 is true.

How much is the charge? 90-0=90 (more is 90, less is just enough, that is 0)? This 90 is the law.

It is as good as the law.

Every reality is equal to law, and there is 1 individual. In fact, it is to divide usage with reality.

90/45=2 people. (2 copies = 1 copy, so it is 2 people)

The person who asks the price will get the price according to the number of people.

The topic says that it is just right to give 50 yuan to each person, and we work out * * *, two people.

50*2= 100 yuan.

The answer is that it takes 100 yuan for two people to buy a dog.

It can be seen here that the Nine Chapters of Calculations was written 1800 years ago, and the concept of algebraic equations was not assumed at that time.

But we can solve this problem of binary linear equations.

This problem can be solved quickly by setting x and y.

People before 1800 can't understand the equation, so they use the concept of "surplus and deficiency" to calculate the number of people through the difference.

This was very advanced in the world at that time, Europe was still in the stage of multiplication and division, and China had begun to sprout algebra.