For a book by mail, the price of each book is a yuan, plus 10% of the book as the postage. For n books, the total amount is y yuan, then y = (), when a = 1.2N, n = 36, y value is ()

y=an(1+10%)
That is y = 1.1an
a=1.2,n=36
Then y = 1.1 × 1.2 × 36 = 47.52

How to learn algebra in grade seven?

As the relationship between numbers, when there are multiple algebraic expressions, they are calculated from the innermost layer and solved layer by layer

What's the meaning of algebra in seventh grade?
Mathematics content of grade one!

Algebra is to replace numbers with symbols or letters. An algebraic expression is an expression with non - concrete values or concrete values
For example: 1 + 3 = 4 is not an algebraic expression, while 1 + a = Z is

The application of mathematical algebra in Grade Seven
To be representative, it's better to talk about the distance

（1） Travel problems: 1. From a to B, it takes 3.6 hours for someone to walk more than by bus. The known walking speed is 8 kilometers per hour, and the bus speed is 40 kilometers per hour. Suppose that the distance between a and B is x kilometers, then the equation is________________ 2. Party A and Party B set out at the same time at a distance of 18 kilometers

Let me give you the following formulas, each of which has a serial number in front of it, so that you can find an algebraic formula,
Categorize them, such as monomials or polynomials, and fill in the serial numbers in the horizontal sound to seek such questions
The more answers, the better. Thank you very much

Remember to add brackets to the mathematical blank filling algebra
① Add sodium carbonate to hydrochloric acid gradually, and bubble immediately. ② add hydrochloric acid to sodium carbonate gradually, and bubble does not appear at first, and then bubble
Why?

Because of excessive hydrochloric acid, the reaction is: 2HCl + Na2CO3 = 2nacl + H2O + CO2 (gas). 2. When hydrochloric acid is gradually added to sodium carbonate, there is no bubble at first, and then bubbles. Because hydrochloric acid is a small amount at the beginning, the reaction is

What is the age difference? How to find the age difference of a place?
How to calculate monthly precipitation and annual precipitation?
The words should be easy to understand

1. In a year, the difference between the highest and lowest monthly average temperature is called annual temperature range
Near the equator, the length of day and night is almost the same, the difference of heat budget between the hottest month and the coldest month is small, and the annual temperature range is very small; the higher the latitude, the more obvious the distinction between winter and summer, and the greater the annual temperature range
The annual temperature range in China is relatively large, because the latitude span in China is very large
Annual temperature range
The difference between the average temperature of the hottest month and the coldest month in a year is called the annual temperature difference. The size of the annual temperature difference varies with latitude, land and sea distribution, topography, etc. the annual temperature difference generally increases with the increase of latitude. The annual temperature difference in low latitude areas is very small, only 1-2 ℃; the annual temperature difference in middle latitude areas increases, In low latitudes, the length of day and night is almost the same in a year, and the change of solar height angle at noon is very small, so the annual temperature range is very small. In middle and high latitudes, the solar height angle at noon is large in summer, and the time of day is long; in winter, it is opposite, At the same latitude, the annual temperature range on land is larger than that on the sea. In the middle latitude inland, the annual temperature range can reach 30-40 ℃, while that on the sea is only 10-15 ℃, The annual temperature range of convex land is less than that of concave land, and that of vegetation covered area is less than that of bare land
In a year, the difference between the highest and lowest monthly average temperature is called annual temperature range. Its size is related to latitude, sea land distribution and other factors. Near the equator, the length of day and night is almost the same, the difference of heat budget between the hottest month and the coldest month is small, and the annual temperature range is very small. The higher the latitude, the more obvious the distinction between winter and summer, and the greater the annual temperature range
In general, the annual temperature range of the temperate ocean is 11 ℃ and that of the continent is 20-60 ℃
The annual temperature range also varies with the weather conditions. The annual temperature range is small in the areas with more clouds and rain, and large in the areas with less clouds and rain
2. It is usually measured with a rain gauge and observed twice a day at fixed time (8 o'clock and 20 o'clock). The unit is mm. The sum of annual precipitation is called annual precipitation

How many times do we watch the temperature in China? It's Beijing time. What basic principles do we advocate for all countries in the world? There are more than ten Mingzi in developed countries in the world

Four times, at 8:14:20:2, they respected each other's sovereignty and integrity of the ridge and soil, did not infringe on each other, did not interfere in each other's internal affairs, had peace and mutual benefit, Britain, France, Germany, Italy, the Netherlands, the United States, Canada, Australia and New Zealand

Geography of Grade 7 Volume 1

The equator is slightly bulging, and the poles are slightly flat. Turning from west to East, time begins to change. North and South are latitudes, forming equal circles. East and West are meridians, forming parallel circles. The equator is the longest, and the polarization is the point. 3. The division of the East, West, North and south hemispheres is 20 degrees west longitude and 16 degrees east longitude

What are the principles of China's regional economic development?

Adjust measures to local conditions and complement each other's advantages
It's absolutely right. It's in the third grade of junior high school

For a book by mail, the price of each book is a yuan, plus 10% of the book as the postage. For n books, the total amount is y yuan, then y = (), when a = 1.2N, n = 36, y value is ()