2a²-{-3a+5[4a²-(3a²-a-1)-3]}-5=2a²-{-3a+5[4a²-3a²+a+1-3]}-5=2a²-{-3a+5a²+5a-10}-5=2a²-5a²-2a+10-5=-3a²-2a+5=(3a+5)(1-a)a=3/2 (3x3/2+5)(1-3/2)=19/...