计算：abc-[2ab-(3abc-bc)+4abc其a=2,b=0.5,c=1
问题描述：
计算：abc-[2ab-(3abc-bc)+4abc其a=2,b=0.5,c=1
答
abc-[2ab-(3abc-bc)+4abc]
=abc-(2ab-3abc+bc+4abc)
=abc-2ab-abc-bc
=-2ab-bc
=-2*2*0.5-0.5*1
=-2-0.5
=-2.5