∫x = y =-2
∴A-2b
=2x？ +3xy+2y- 1-2(x？ -xy+x- 1/2)
=2x？ +3xy+2y- 1-2x？ +2xy-2x+ 1
=5xy+2y-2x
=5×(-2)×(-2)+2×(-2)-2×(-2)
=20-4+4
=20
2、A-2B==5xy+2y-2x=(5y-2)x+2y
According to the meaning of the question, 5y-2=0, and the solution is y=2/5.