-(-3a-2b+2c)-{-a+[4a-(a-b-c)-3a]+2c}

问题描述:

-(-3a-2b+2c)-{-a+[4a-(a-b-c)-3a]+2c}

=3a+2b-2c-{-a+[4a-a+b+c-3a]+2c}=3a+2b-2c-{-a+4a-a+b+c-3a+2c}=3a+2b-2c+a-4a+a-b-c+3a-2c=4a+b-5c

-(-3a-2b+2c)-{-a+[4a-(a-b-c)-3a]+2c}
=3a+2b-2c+a-4a+a+b+c-3a-2c
=-3a+3b-3c