已知a与b互为相反数,c与d互为倒数,x=3（a-1）-（a-2b）,y=(c^2)d+d^2-(d/c+c-1).

已知a与b互为相反数,a+b=0
c与d互为倒数,cd=1;
x=3（a-1）-（a-2b）
=3a-3-a+2b
=2a+2b-3
=2(a+b)-3
=2(0)-3
=-3;
y=(c^2)d+d^2-(d/c+c-1)
=c²d+d²-d/c-c+1
=c(cd)+[(cd)d-d]/c-c+1
=c(1)+[(1)d-d]/c-c+1
=c+[d-d]/c-c+1
=c+0-c+1
=1
（3x-2y）/2-(4x-2y）/3
=(-9-2)/2-(-12-2)/3
=-11/2+14/3
=(-33+28)/6
=-5/6