1)√(170^2-80^2) =√(170+80)(170-80) =√(250*90) =√(25*900) =√(5^2*30^2) =5*30 =1502)3次根号20744 =3次根号(2593*8) =2*3次根号25933)√6*√7 ≈2.449*2.646 ≈6.484)3次根号8-3次根号2 = 2-3次根号2 ≈2-1.260 ≈0.74
