Question

ratinalise the denominator
please answer this question​

Answer 1

The Whole concept of rationalizing is to get denominator in form $a^{2} -b^{2}$

Explanation:-

Multiply and divide by $\frac{7+2\sqrt{5} }{7+2\sqrt{5}}$

⇒   $\frac{1}{7-2\sqrt{5}}$  ×  $\frac{7+2\sqrt{5} }{7+2\sqrt{5}}$

⇒ $\frac{7+2\sqrt{5} }{(7-2\sqrt{5})*({7+2\sqrt{5}})}$

⇒ $\frac{{7+2\sqrt{5}}}{(7)^{2}-(2\sqrt{5} )^{2} }$

⇒ $\frac{{7+2\sqrt{5}}}{49-(2*2*5) }$

⇒ $\frac{7+2\sqrt{5} }{49-20}$

⇒ $\frac{7+2\sqrt{5} }{29}$  is the answer

Hence, Rationalized the denominator