Real numbers can be defined as the union of both the rational and irrational numbers. They can be both positive or negative and are denoted by the symbol “R”. All the natural numbers, decimals, and fractions come under this category. See the figure, given below, which shows the classification of real numerals.

1)- plants absorb carbon dioxide and provide oxygen . it is said that an average sized tree can absorb like 22 kg of co2 per year
2)- plants beings the herbivores support and provides food to other level of food web
3)- they can fix nitrogen in the soil. some plant root nodules can fix nitrogen
 eg:- rhizobium , azetobacter
4)- they can provide us shelter . Under a tree , there are thousands of insects and birds survive
5)- plants avoid soil erosion . Their roots can hold up the soils together
6)- the leaves of plants avoid and reduces the pressure of falling rain on the soil
7)- it is said that trees can reduce sound pollution

The primary function of photosynthesis is to convert the energy from the sun into chemical energy for food. With the exception of certain plants utilizing chemosynthesis, all plants and animals in Earth's ecosystem are ultimately dependent on the sugars and carbohydrates produced by plants through photosynthesis. Photosynthesis is the process by which plants and other things make food. It is an endothermic (takes in heat) chemical process that uses sunlight to turn carbon dioxide into sugars that the cell can use as energy. As well as plants, many kinds of algae, protists and bacteria use it to get food.

Chlorophyll is mainly present in the thylakoids of the chloroplast. It helps to absorb light and transfer that light energy by resonance energy transfer to a specific chlorophyll pair in the reaction center of the photosystems. This sunlight absorbed helps in the process of photosynthesis. 

BODMAS stands for Bracket, Of, Division, Multiplication, Addition, and Subtraction. The BODMAS is used to explain the order of operation of an mathematical expression. In some regions, the BODMAS is also known as PEDMAS which stands for Parentheses, Exponents, Division, Multiplication, Addition and Subtraction. According to Bodmas rule, if an expression contains brackets ((), {}, []) we have to first solve or simplify the bracket followed by of (powers and roots etc.), then division, multiplication, addition and subtraction from left to right. 

The process by which a seed grows into a new plant is called germination.

 When the seed get all the necessary things like air, water, warmth, space and nutrients from the soil the process of germination starts.

First of all, any informal letter opening should start with a greeting. If you do not know the name of the addressee, use “Dear Sir” or “Dear Madame.” If you know the name of the addressee and are in the working relationship: write “Dear Dr. Davidson” (Dr. = Doctor)!

A informal letter can be written in nearly any way you choose, but there are a few organizational guidelines you can follow if you are unsure of what to write or how to format your letter. The perfect informal letter consists of three sections:

1. Opening
2. Body text
3. Closing

There is one final part of an informal letter that doesn't need listed here: the signature, which consists of no more than a farewell remark and your name. Learn about each of the three main parts of an informal letter below.

Opening

The first step is addressing your reader. But how do you address someone in English?

This is fairly straightforward and is usually not as important as it would be with a business or formal letter. There are still a few things that you should know in terms of addressing someone properly in an informal latter.

First, British English does not employ the use of a period after abbreviated titles, but American English does.

• Mr Johnson (British English)
• Mr. Johnson (American English)

  Body

  The contents of your letter should be written in a personal and friendly tone. However, it's important to adjust your use of language to the person you are writing to. A good way of assessing how you should write is to think about how you would interact with the person you are writing to in real life. Also, keep in mind that the people of England and America are fond of exchanging social niceties.

  For example, they like asking a few polite questions "How are you?" or "How was your holiday?" In general, they are not as direct as most Europeans.

  Subjects to Include in the Body

• State your reason for writing
• Expand on what you mentioned in the first paragraph
• Ask about the person you are writing to
• Make some concluding remarks
• Invite the person to write back

• Closing

  The closing is where you summarize your letter and say goodbye to the reader. The examples below offer some ideas of what to write in the closing section of your informal letter.

  Examples of Closing Sentences

• I am looking forward to seeing you.
• I can't wait to see you soon.
• I can't wait to hear from you.
• I am looking forward to hearing from you soon.
• I hope to hear from you soon.
• See you soon.
• Send my love to...
• I hope you are doing well.

19/2 = 9 1/2 is the mixed fraction.

The distance from the centre to the circumference is the radius.

4 3/8 + 2 1/8

= 35/8 + 17/8

= (35 + 17)/8

= 52/8

= 13/2

Liter is the standard unit of capacity and the smaller unit of capacity is milliliter.

In the first stanza, the poet is talking of the present time when he has to choose one of the two roads.

HCF or Highest Common Factor of two or more numbers is the greatest factor which divides the numbers. For example, 2 is the HCF of 4 and 6. LCM or Least common multiple is the smallest number which is divisible by two or more given numbers. For example, LCM of 2 & 3 is 6. LCM can be used before the addition, subtraction, or comparison of fractions can take place. The LCM of more than two integers also happens to be well-defined: it is the smallest positive integer whose division can take place by each of them. One can find the highest common factor by carrying out the multiplication of all the factors which appear in both lists. Therefore, the HCF of 60 and 72 is 2 × 2 × 3 which turns out to be 12.