Question

Which of the following not an irrational number (a) 5-√3 (b) √5+√3 (c) 4+√2 ( d) 5+√9

Answer 1

Option (d) is not an irrational no. . It is rational as --- 5+√9 = 5+3=8 which is a rational no.

Answer 2

Answer:

Option d is correct.

Step-by-step explanation:

To find : Which of the following not an irrational number ?

Solution :

Irrational number is the number which cannot be written in form of p/q where p and q are integers and q is non-zero.

Irrational number are non-terminating and non-repeating.

From the given options,

a) $5-\sqrt3$

$\sqrt{3}$ is irrational number so subtracting rational and irrational gives irrational number.

So, $5-\sqrt3$ is irrational number.

b) $\sqrt5-\sqrt3$

$\sqrt{3}$ and $\sqrt{5}$ both are irrational number so adding them gives you an irrational number.

So, $\sqrt5-\sqrt3$ is irrational number.

c) $4+\sqrt2$

$\sqrt{2}$ is irrational number so adding rational and irrational gives irrational number.

So, $4+\sqrt2$ is irrational number.

d) $5+\sqrt9$

$\sqrt{9}=3$ is rational number.

$5+\sqrt9=5+3=8$

It gives rational number.

So, $5+\sqrt9$ is rational number or not an irrational number.