A rational number is simply a term that can be expressed as a fraction. Otherwise, that is an irrational number. So, you can use a calculator to verify if the number is rational or not.
The key characteristic of an irrational number is when it contains a long line of decimal places. For example, the term π and the Euler's number e are irrational numbers. The exact values of π and e are 3.14159 and <span>2.71828182846, respectively. In reality, those decimal places go on a long way. Particularly, </span>π<span> has a total of 2.7 trillion digits. Numbers inside radicals or roots can also be irrational numbers. For example </span>√3 is irrational because it is equal to 1.732050808. However, not all radicals are irrational. For example √15.3664 is equal to 98/25 or 3.92. That is a rational number. So, therefore, use the calculator to know the exact value of the term to properly distinguish rational from irrational.
Answer:
750 books
Step-by-step explanation:
Let there be "x" number of books in the 3rd room
Now,
2nd room has 3 times as 3rd room, so we can write:
Second Room = 3x
Also, there are 1960 MORE books in 1st room than 2nd room, so we can write:
First Room = 3x + 1960
In total there are 7210 books in all three rooms, thus we can write:
First Room + Second Room + Third Room = 7210
Now, replacing the first 2 equations in this, we get:
3x + 1960 + 3x + x = 7210
Solving for x:

"x" is indeed what we are looking for. Thus,
There are 750 books in the third room
30=5(x+1)
30÷5=6
6=x+1
6-1=5
x=5
Please include the inequality