8X-8Y=240 5X-3Y=270怎样解

(4x-2y-z)-{5x[8y-2y-(x+y)]-x+(3y-10z)]=? kuaihuajian 【2(x-y)^3-8(x-y)^2(x+y)+6y(x-y)^2】/2(x-y)^2= 3x-2y=9 x-3y=2 x+y=5 x+2y=3 y=x 2x+y=8 x+y=1 5x-2y=8 3x-y=7 2x-y=3x表示y和用y表示x 已知x.x+y.y-6x-8y+25=0,求3x.x+5y的值 (x+y)/y=8/3则x/y=__ y/x-y=___ (x+y)/y=8/3则x/y=__ y/x-y=___ 12y(x-y)^2-8(x-y)^3=? {x+y=1 ,xy=-6{x(2x-3)=0,y=x²-1{(3x+4y-3)(3x+4y+3)=0,3x+2y=5{(x-y+2)(x+y)=0,x²+y²=8{(x+y)((x+y-1)=0,(x-y)(x-y-1)=0 （x+y-5)*（x+y-5)+（x-y+3)=0 x*x-y*y 已知:3x-5y=0,求x/y,x-y/y,x-y/x 7y=x+3,8y=x+5 7y=x+3,8y-5=x 7y=x+3,8y+5=x x+y=8,5x+3y=34; (7y-3x)-(8y-5x)= 5X+8Y=3Y+6X x+y=5,2x+y=8,x-2y=0,3x+2y=8