x=3(a-1)-(a-2b)
=3a-3-a+2b
=2(a+b)-3
=-3
y=c^2×d+d^2-(d/c+c-1)
=c+d^2-d/c-c+1
=d^2-d/c+1
(接下去算不了,看来是我理解题目有误)