已知a与b互为相反数,c与d互为倒数,x=3(3-1)-(a-2b),y=c^2d+d^2-(d/c+c-1),求2x+y/3 - 3x-2y/6的指

题目

已知a与b互为相反数,c与d互为倒数,x=3(3-1)-(a-2b),y=c^2d+d^2-(d/c+c-1),求2x+y/3 - 3x-2y/6的指
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^2d+d^2-(d/c+c-1),求2x+y/3 - 3x-2y/6的值

答案

x=3(a-1)-(a-2b)
=3a-3-（a+2a)
=-3
y=c^2d+d^2-(d/c+c-1)
=c+d^2- (d^2+1/d-1)
=1/d+d^2-d^2-1/d+1
=1
2x+y/3 - 3x-2y/6
=-x
=3