先化简,再求值 3xy-[2x-2xy-(3x+xy)-5y],其中x-2的绝对值的平方+（y-3)的平方=0

|x-2|²+(y-3)²=0x-2=0,y-3=0x=2,y=3原式=3xy-[2x-2xy-(3x+xy)-5y]=3xy-(2x-2xy-3x-xy-5y)=3xy-2x+2xy+3x+xy+5y=(3xy+2xy+xy)+(-2x+3x)+5y=6xy+x+5y当x=2,y=3时原式=6×2×3+2+5×3=36+2+15=53