(x-6)(y+12)=(x+4)(y-4)=xy 谁来教教我?

8x-8y-3x-3y=-12,6x+6y-8x+4y=16 填空题 x+y/4=x-y/6=3x+12y+5/8 x= y= 解方程组：x+y/2+x-y/3=6 4(x+y)-5(x-y)=12 解方程组{2(x-y)/3 - x+y/4=-1 6(x+y)-41(x-y)=12 8（x-y)=3（x+y)-12 6（x+y)=4（2x-y)+16 8（x-y)=3（x+y)-12 6（x+y)=4（2x-y)+16 {3(x+y)-4(x-y)=4 {x+y/2 + x-y/6=1 x+y/2+x-y/3=6,4(x+y)-3(x-y)=-20 {(x+y)/2+(x-y)/3=6 4(x+y)-3(x-y)=-20 4(x+y)-3(x-y)=-20,2/x+y+3/x-y=6 （x+y）/2- x-y/2=6 3(x+y)=4(x-y) x+y/3+x-y/2=6 4(x+y)-2(x-y)=40 x^2+y^2+4x-6y+12=0.求x^y的值 已知X.Y是实数,且X²+Y²-4X+6Y+12=0 求X+Y的最值,X-Y的最值 已知X.Y是实数,且X²+Y²-4X+6Y+12=0 求X+Y的最值,X-Y的最值 已知x,y∈R,满足x²+y²-4x-6y+12=0 1.y/x的范围,2.x²+y²的范围 3已知x,y∈R,满足x²+y²-4x-6y+12=01.y/x的范围,2.x²+y²的范围 3.x+y的范围 化简求值:(x+y)-(2x+1/2y)-(3x+1/6y)-(4x+1/12y)-(5x+1/20y)-.(10x+1/90y) ,其中x=1,y=-2 若(-x+6):(x-y):(4x+y)=3:14:1,求x+y