1/2x-2(x-1/3y的平方)+(3/2+1/3y的平方)
=1/2x-2x+2/3y的平方+3/2+1/3y的平方
=-3/2x+y²+3/2
x=-2 y=-0.5
-3/2x+y²+3/2
=3+0.25+1.5
=4.75对不起啊，看错题了，应该是x=2/3 y=-2,麻烦你了x=2/3 y=-2-3/2x+y²+3/2=-1+4+1.5=4.5