Question

(5-√21)+(3+√21) is rational or not??​

Answer 1

Answer:

8

Step-by-step explanation:

$(5 - \sqrt{21} ) + (3 + \sqrt{21} )$

$= 5 - \sqrt{21} + 3 + \sqrt{21}$

$= 5 + 3 + \sqrt{21} - \sqrt{21}$

$= 8$

Hope this helps

Please mark as brainliest

Answer 2

Answer :

Yes , it's a rational number.

Step-by-step explanation:

Let's Find it out.

What is a rational number ?

A rational number is a number which can be expressed in p/q form , where q≠0.

Let's try simplifying it.

$\sf \: (5 - \sqrt{21} ) + (3 + \sqrt{21} )$

$\sf \implies \: 5 - \sqrt{21} + 3 + \sqrt{21}$

$\sf \implies \: 5 + 3 - \sqrt{21} + \sqrt{21}$

$\sf \implies \: 8$

We get answer as 8.

As we know a rational number is a number which can be expressed in p/q form where p and q are integers and q≠0 .

The p/q representation of 8 will be :

$\dfrac{8}{1} ( \blue \longrightarrow \: \dfrac{p}{q} . \: q \neq \: 0)$

Hence it is a rational number.

What you need to know ?

• There exists two types of numbers Rational and irrational.

☞ Rational number are numbers which can be represented in p/q form where p and q are integers are q ≠ 0.

☞ Irrational numbers are just opposite of the same. It cannot be represented in p/q form.

☞ When we we combine both rational and irrational numbers , we get real numbers.