:|x+二分之一|+(y-3)的平方=0∴x+1/2=0y-3=0∴x=-1/2y=3(3x+2y)的平方-2(x-y)(x+y)+3(x+y)(x-2y)=9x²+12xy+4y²-2x²+2y²+3x²-3xy-6y²=10x²+9xy=10/4-27/2=-11