Question

If $x+\sqrt{y}=2+\sqrt{7}$ where, x is a rational number and y is an irrational number. Then the value of y = ___

• A. 2
• B. 9
• C. 7
• D. $\sqrt{7}$

Answer 1

The correct option is C

7

We know that,

If $x+\sqrt{y}=a+\sqrt{b}$, where x and a are both rational numbers and $\sqrt{y}$ and $\sqrt{b}$ are both surds, then x = a and y = b.

Similarly here its given that, $x+\sqrt{y}=2+\sqrt{7}$ where x is a rational number and y is an irrational number.

So, x = 2 and y = 7