x-y=3 3x-8y=14的解

方程组4=x+y,8=3x-y求x,y的解 解方程组 4(x+y)-(2x-y)=14 ,3(x+y)-2(2x-y)=8 已知x,y为正整数,并且x*y+x+y=71,x*x*y+x*y*y=880,求3*x*x+8*x*y+3*y*y的值 已知x-y=3,求[（x+y)(x-y)-(x-y)^2+2y(x-y)]除以的值 (-x+6):(x-y);(4x+y)=3;14:1,求x+y的值. 已知x.x+y.y-6x-8y+25=0,求3x.x+5y的值 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, 【2(x-y)^3-8(x-y)^2(x+y)+6y(x-y)^2】/2(x-y)^2= 若2/x-1/y=3,求[y/x-y/x-y(x-y/x-x+y)]/x-2y/x的值 6(x+y)的平方-11(x+y)(x-y)+3(x-y)的平方=? y=3(x-y),x=2(x-y)求x,y的值 (x+y)/y=8/3则x/y=__ y/x-y=___ (x+y)/y=8/3则x/y=__ y/x-y=___ 已知|3x-y|+|x+y|=0,求x-y除以x*y的值. 若x-y不等于0,2x-3y=0,则分式(10x-11y)/(x-y)的值是（）?(10x-11y)/(x-y) =[(8x-8y)+(2x-3y)]/(x-y) =8为什么8X-8Y=8？(10x-11y)/(x-y)=[(8x-8y)+(2x-3y)]/(x-y)=8+(2x-3y)]/(x-y)=8+0=8 6(x-y)-2(x+y)=14 3(x-y)+(x+y)=5 12y(x-y)^2-8(x-y)^3=? 已知x-y/y=8/3,求x+y/y的值