Question

Rationalizati numitorul raportului:
a) $\frac{7}{3 \sqrt{21} }$ b) $\frac{ \sqrt{6} }{5-2 \sqrt{6} }$

Answer 1

a)  7/(3√21) = 7·√21/63 = √21/9
b)  √6 /(5- 2√6) ·(5 + 2√6)/(5 +2√6) = (5√6 + 12)/1 = 5√6 + 12