Question

Помогите пожалуйста!!!Очень Вас прошу!!!

Answer 1

1)2 / √7 = 2√7 / 7

2)√2 / (√2 + 1) = √2(√2 - 1) / (√2+1)(√2-1) = √2(√2 - 1) / (2 - 1) = √2(√2-1) / 1 = 2 - √2

 

3)4 / √11 = 4√11 / 11

4)√5 / (√5 - 2) = √5(√5 + 2) / (√5 - 2)(√5 + 2) = √5(√5+2) / 5 - 4 = √5(√5+2) = 5 + 2√5

Answer 2

$frac{2}{sqrt{7}}=frac{2sqrt{7}}{7}$

$frac{4}{sqrt{11}}=frac{4sqrt{11}}{11}$

$frac{sqrt{2}}{sqrt{2}+1}=frac{(sqrt{2})(sqrt{2}-1)}{(sqrt{2}+1)(sqrt{2}-1)}=frac{2-sqrt{2}}{1}=2-sqrt{2}$

$frac{sqrt{5}}{sqrt{5}-2}=frac{(sqrt{5})(sqrt{5}+2)}{(sqrt{5}-2)(sqrt{5}+2)}=frac{5+2sqrt{5}}{1}=5+2sqrt{5}$