a=-3,b=-5,c=5分之1
(3a-c)+(-2a-c)-(2a+b-c+5)+(2a-b+c+5)-2bc的值
=3a-c-2a-c-2a-b+c-5+2a-b+c+5-2bc
=a-2b-2bc
=-3-2*(-5)-2*(-5)*(1/5)
=-3+10+2
=9
a=-3,b=-5,c=5分之1
(3a-c)+(-2a-c)-(2a+b-c+5)+(2a-b+c+5)-2bc的值
=3a-c-2a-c-2a-b+c-5+2a-b+c+5-2bc
=a-2b-2bc
=-3-2*(-5)-2*(-5)*(1/5)
=-3+10+2
=9