║(√6-√5)(√5+√6)║-3×(√20-2×║√5-2) = -11
(║√75-4√3║-║√27-√108║+1)×(1+2√3) = -11
║4√2-3√8+5║×║-2√2-5║ = - 4√2
║3√5-2√125+10║×║7√5-10║ = 345 - 140√5
