{2x+3y=7,{3x+2y=8的解

已知x-y=3,求[（x+y)(x-y)-(x-y)^2+2y(x-y)]除以的值 求几个方程组的答案 ｛2x+y=2 {3x-y=7 x=?y=?{x+2y=50 {3x=2y+6 x=?y=?{x+y=40 {10x+8y=370 x、y=?{x+y=5.8 {y=3x+0.6 x=?y=? 【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 用适当的方程解方程组2(x+y)-(x-y)=8 (x+y)-2(x-y)=15 2x+1=5(y+2) (3x+2)-2(y+7x)=16 已知（x+y）2 =2,(x-y)3 =3,求(x+y)7(x-y)2(x+y)3(y-x)4 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, y=3(x-y),x=2(x-y)求x,y的值 已知(3x+1)(3x-3)-3x+2)^2=-7,(y+7)(y-7)-y(y-7)=0,求8y^2-5y(-y+3x)+4y(-4y-5/2x)的值 x+y=1 5x-2y=8 3x-y=7 2x-y=3x表示y和用y表示x 已知实数x.y满足根号(x+y-8)+根号(8-x-y)=根号(3x-y-4)+根号(x-2y+7),求x,y 12y(x-y)^2-8(x-y)^3=? 若(x-y)/(x+y)=3 则(x+2y)/(6x-7y)等于 x+y+z=7,2x+3y+4y=20求x,y,z的正整数解 已知方程组2x-y=7,3x+y=8 x和y的解的过程 3x+2=y 5x+4=y 7x+6=y 9x+8=y 11x=y怎么解 4x-(2x+y+16)/2=-6y 2x+3y=7-x-2y4x-(2x+y+16)/2=-6y 2x+3y=7-x-2y求方程组的解 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