Question

the number obtained on rationalising the denominator of 1/√7-2is​

Answer 1

Answer:

(a+b)(a−b)=a2−b.

Multiply and divide 7−21 by 7+2 to get 

7−21×7+27+2=7−47+2=37+2 

Answer 2

Answer:

$\frac{\sqrt{7}+2 }{3}$

Step-by-step explanation:

1/√7-2

=$\frac{1}{\sqrt{7}-2 }$ × $\frac{\sqrt{7}+2 }{\sqrt{7}+2 }$

=$\frac{\sqrt{7} +2}{7-4}$

=$\frac{\sqrt{7}+2 }{3}$