Question

Задания по корням. Помогите пожалуйста!!!

Answer 1

3.

б)

$frac{4a-3}{2sqrt a-sqrt3}=frac{(2sqrt a-sqrt3)(2sqrt a+sqrt3)}{2sqrt a-sqrt3}=2sqrt a+sqrt3$

4.

a)

$frac{3}{2sqrt3}=frac{3sqrt3}{2sqrt3cdotsqrt3}=frac{3sqrt3}{2cdot3}=frac{sqrt3}{2}$

б)

$frac{10}{3-sqrt5}=frac{10(3+sqrt5)}{(3-sqrt5)(3+sqrt5)}=frac{10(3+sqrt5)}{9-5}=frac{10(3+sqrt5)}{4}=frac{5(3+sqrt5)}{2}$

5.

$frac{1}{2sqrt3+1}-frac{1}{2sqrt3-1}=frac{2sqrt3-1}{(2sqrt3+1)(2sqrt3-1)}-frac{2sqrt3+1}{(2sqrt3-1)(2sqrt3+1)}=$

$frac{2sqrt3-1}{12-1}-frac{2sqrt3+1}{12-1}=frac{2sqrt3-1}{11}-frac{2sqrt3+1}{11}=frac{2sqrt3-1-2sqrt3-1}{11}=- frac{2}{11}$