Ответы и объяснения

2014-03-12T20:24:33+00:00
Х^2=V(56+2V720)
X^2=V(56+2•V(144•5))
X^2=V(56+2•12V5)
X^2=V(56+2•6•2V5)
X^2=V(6^2+2•6•2V5+(2V5)^2)
X^2=V(6+2V5)^2
X^2=6+2V5
X=V(6+2V5)