Question

Fie a=3(√5+7)-5(3+√5) si b=6+√20
Demonstrati ca a=6-2√5
Cine ma ajuta dau coroana!!!

Answer 1

a=3$\sqrt{5}$+3*7-5*3-5*$\sqrt{5}$
a=-2$\sqrt{5}$+21-15=-2$\sqrt{5}$+6
a=6-2$\sqrt{5}$