因为ab互为相反数,cd互为倒数所以 a+b=0, cd=1(1)6-2a-2b+3cd =6-2(a+b) +3cd =6-0+3 =9 (2)(a+b)/(a+b+c)-2cd+m 1)当m=2时 (a+b)/(a+b+c)-2cd+m = 0/(a+b+c)- 2+2 =0 2) 当 m=-2 时 (a+b)/(a+b+c)-2cd+m = 0/(a+b+c)- 2-2 =-4
(1)6-2a-2b+3cd =6-2*(a+b)+3cd=6-0+3*1=9 (2)(a+b)/(a+b+c)-2cd+m
=0/c-2*1+m=m-2当m=2时,多项式等于0当m=-2时,多项式等于-4
(1)9(2)-4或0