Question

trục căn ở mẫu các biểu thức \(\frac{5}{\sqrt{5}}\); \(\frac{5}{2+\sqrt{3}}\)

Answer 1

Ta có:

\(\frac{5}{\sqrt{5}}=\frac{5.\sqrt{5}}{5}=\sqrt{5}\)

\(\frac{5}{2+\sqrt{3}}=\frac{5\left(2-\sqrt{3}\right)}{4-3}=\frac{10-5\sqrt{3}}{1}=10-5\sqrt{3}\)

Hok tốt nha

Answer 2

\(\frac{5}{\sqrt{5}}=\frac{5\sqrt{5}}{\sqrt{5}.\sqrt{5}}\frac{5\sqrt{5}}{5}=\sqrt{5}\)

Answer 3

\(\frac{5}{2+\sqrt{3}}=\frac{5\left(2-\sqrt{3}\right)}{\left(2+\sqrt{3}\right)\left(2-\sqrt{3}\right)}=\frac{5\left(2-\sqrt{3}\right)}{4-3}=5\left(2-\sqrt{3}\right)\)