已知/X-Y-1/+(XY+3)的平方=0,求(-2XY+2X+3Y)-(3XY+2Y-2X)-(X+4Y+XY)的值!
问题描述:
已知/X-Y-1/+(XY+3)的平方=0,求(-2XY+2X+3Y)-(3XY+2Y-2X)-(X+4Y+XY)的值!
已知/X-Y-1/+(XY+3)的平方=0,求(-2XY+2X+3Y)-(3XY+2Y-2X)-(X+4Y+XY)的值
急!
答
/X-Y-1/+(XY+3)的平方=0X-Y-1=0 XY+3=0X-Y=1 XY=-3(-2XY+2X+3Y)-(3XY+2Y-2X)-(X+4Y+XY)=-2XY+2X+3Y-3XY-2Y+2X-X-4Y-XY=-2XY-3XY-XY+2X+2X-X+3Y-2Y-4Y=-6XY+3X-3Y=-6×(-3)+3=18+3=21