👤

(1+√5-√3)(1-√5-√3)+(1-√7+√3)(1+√7+√3) este egal cu...

Răspuns :

(1+√5-√3)(1-√5-√3)+(1-√7+√3)(1+√7+√3) =
=
(1-√3+√5)(1-√3-√5)+(1+√3-√7)(1+√3+√7) =
=(1-√3)²-(√5)²+(1+√3)²-(√7)²=
=1-2√3+3-5+1+2√3+3-7=
=4-5+4-7=-4