Răspuns:
a= (1/rad3)-(1/rad12)+(1/rad27)= (rad3)/3-(rad12)/12+(rad27)/27= (rad3)/3-(2rad3)/12+(3rad3)/27= (rad3)/3-(rad3)/6+(rad3)/9=(6rad3-3rad3+rad3)/18=(4rad3)/18= (2rad3)/9
b= rad6/rad8+ rad54/rad32 = (rad3)/2+rad27/rad16=(rad3)/2+(3rad3)/4= (2rad3)/4+(3rad3)/4= (5rad3)/4
a×b= 10*3/36= 10/12= 5/6