y=(3+x)^2-9=x^2+6x 请谁能告诉我怎么化简得来的?

x-y/x+y=-1/2,x*x-xy-2y*y/x*x-3xy+2y*y的解是多少?同上,请将过程写出, xy²/(x²y-y) × x²/(x²+x)=(x²-3x)/(x²-5x) × 2x-10/(x²-6x+9)=化简求植x²-1/(x²-x-2)除以x/2x-4,其中x=1/2[x-x/(x+1)]除以[x/(2x-4)] ,其中x=√2+1 4x=9y,求x+y/y;y-x/2x请给我完整过程 3^x+2x=y,x 【2(x-y)^3-8(x-y)^2(x+y)+6y(x-y)^2】/2(x-y)^2= 已知：3x+2y=13,2x-3y=0.求x^2+x-2/x^2+4x+4除以x^2+2x-3/x^2-4乘于x^2+6x+9/x^2-xy-2x+2y的值请高手帮我算出来 急啊急啊 x+y/2+x-y/6=5 2(x+y)-3(x-y)=-2 3(x+y)-2(x-y)=11 4(x+y)+3(x-y)=9 （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 4(x-y)-3(x-y)=9 5(x-y)+2(x-y)=11 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/x-x+y/y-(x+y)(x-y)/y² y/x=2 2(x+y)-3(x-y)=1 6(x+y)+(x-y)=51 {3(x+y)-4(x-y)=4 {x+y/2 + x-y/6=1 6(x-y)-2(x+y)=14 3(x-y)+(x+y)=5