Question

rationalizati numitorul raportului -3/1-radical7​

Answer 1

-3/( 1-√7)=-3(1-√7)/(1-√7) *( 1+√7)

aplicam formula

(a-b) (a+b) =a²-b²  oricare ar fi a,b ∈R

-3(1+√7)/(1-7 ) =-3(1+√7)/ -6

reducem -3 si -6 obtinem 1/2 = (1+√7)/2