Question

30 баллов 1 вариант
Пожалуйста

Answer 1

1)
$3sqrt{7}=sqrt{3^2*7}=sqrt{63}\4sqrt{5}=sqrt{4^2*5}=sqrt{80}\3sqrt{7}<4sqrt{5}$

2)
$=frac{(sqrt{3})^2-sqrt{3}}{2sqrt{3}}=frac{sqrt{3}(sqrt{3}-1)}{2sqrt{3}}=frac{sqrt{3}-1}{2}$

$frac{4b-2}{2sqrt{b}-sqrt{2}}=frac{(2sqrt{b})^2-(sqrt{2})^2}{2sqrt{b}-sqrt{2}}=frac{(2sqrt{b}-sqrt{2})*(2sqrt{b}+sqrt{2})}{2sqrt{b}-sqrt{2}}=2sqrt{b}+sqrt{2}$

3)
a)
$frac{2}{sqrt{7}}=frac{2*sqrt{7}}{sqrt{7}*sqrt{7}}=frac{2sqrt{7}}{7}$

б)
$frac{sqrt{2}}{sqrt{2}+1}=frac{sqrt{2}*(sqrt{2}-1)}{(sqrt{2}+1)*(sqrt{2}-1)}=frac{sqrt{4}-sqrt{2}}{(sqrt{2})^2-1^2}=2-sqrt{2}$