Bài làm:
\(\frac{\sqrt{5}+2}{\sqrt{5}-2}=\frac{\left(\sqrt{5}+2\right)^2}{\left(\sqrt{5}-2\right)\left(\sqrt{5}+2\right)}=\frac{5+2.2.\sqrt{5}+4}{5-4}\)
\(=9+4\sqrt{5}\)
Học tốt!!!!
\(\frac{\sqrt{5}+2}{\sqrt{5}-2}=\frac{5+2\sqrt{5}+4+2\sqrt{5}}{\sqrt{5}^2-2^2}\)
\(=\frac{9+4\sqrt{5}}{5-4}=9+4\sqrt{5}\)
@Học tốt@
Trả lời
\(\frac{\sqrt{5}+2}{\sqrt{5}-2}=\frac{\left(\sqrt{5}+2\right).\left(\sqrt{5}+2\right)}{\left(\sqrt{5}-2\right).\left(\sqrt{5}+2\right)}\)
\(=\frac{5+4\sqrt{5}+4}{5-4}\)
\(=\frac{9+4\sqrt{5}}{1}\)
\(=9+4\sqrt{5}\)