Question

rationalise the denimimator 2/7+under root 5

Answer 1

$\frac{2}{7 + \sqrt{5} } \times \frac{7 - \sqrt{5}}{7 - \sqrt{5}} \\ = \frac{14 - 2 \sqrt{5} }{ ({7})^{2} - ( \sqrt{5} ) ^{2} } \\ = \frac{14 - 2 \sqrt{5} }{49 - 5} \\ = \frac{14 - 2 \sqrt{5} }{44} \\ = \frac{2(7 - \sqrt{5}) }{44} \\ = \frac{7 - \sqrt{5} }{22}$

Answer 2

Answer:

2.521

Step-by-step explanation:

2/7=0.285.

√5=2.236.

0.285+2.236=2.521