已知A=3a-6a+1,B=-2a^2+3,C=4a,计算(B+C)-{A-(B-C)}.
问题描述:
已知A=3a-6a+1,B=-2a^2+3,C=4a,计算(B+C)-{A-(B-C)}.
答
(B+C)-{A-(B-C)}
=B+C-A+(B-C)
=B+C-A+B-C
=2B-A
=2(-2a²+3)-(3a-6a+1)
=-4a²+6-3a+6a-1
=-4a²+3a+5