化简求值题:一.5abc-{2a²b-[3abc-(4a²b-a²b)]}; (其中a=1

5abc-{2a²b-[3abc-(4a²b-a²b)]}
=5abc-2a²b+[3abc-3a²b]
=8abc-5a^2b
=8*1*2*1/4-5*1*2
=4-10
=-6