已知:|x+二分之一|+(y-3)的平方=0,求:代数式(3x+2y)的平方-2(x-y)(x+y)=3(x+y)(x-

:|x+二分之一|+(y-3)的平方=0
∴x+1/2=0
y-3=0
∴x=-1/2
y=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