3x-y=54x+7y=1

3x-y=54x+7y=1 初二上学期方程题 4x+y=5 5x+4y=63x-2y=1 2x+3y=13x-2y=7 7x+5y=32x+3y=17 2x-y=-4x+5y=6 2x+y=23x-6y=4 3x+2y=52x+y=73x-4y=53x+y=1x-2y=-1x+y=42x+3y=92x-3y=74x+5y=3x+y=20004x+6y=90003x+5y=113x-2y=42x+3y=215x-2y=5x+y=54x+3y=182x+3y=16x+4y=132x+3y=40x 已知：2x+y=6,x-3y=1 求7y(x-3y)(x-3y)-2(3y-x)(3y-x) 5(x-y)³-3（x-y）²+7(x-y)-5(x-y)³+（x-y）²-5（x-y）,其中,x-y=1/3.5(x-y)³-3（x-y）²+7(x-y)-5(x-y)³+（x-y）²-5（x-y）,其中,x-y=1/3先化简,再求值； x+y=1 5x-2y=8 3x-y=7 2x-y=3x表示y和用y表示x y(x+y)+(x-y)²-（x+y）（x-y）,其中x=-1/3,y=3 若2/x-1/y=3,求[y/x-y/x-y(x-y/x-x+y)]/x-2y/x的值 {3(x+y)+3(y+x)=1,3(x+y)+4(y-x)=-1 {6(x-y)-7(x+y)=21 {2(x-y)-5(x+y)=-1 x+2y=2x+y+1=7x-y 求：2x-y? (3x-y)^2+(3x+y)(3x-y),x=1,y=-2 y'=(x-y+1)/(x+y-3)通解 若(x-y)/(x+y)=3 则(x+2y)/(6x-7y)等于 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 变量x,y满足约束条件,x+y>=3,x-y>=-1,2x-y 二元一次方程 ：2(x+y)-(x-y)=3 (x+y)-2(x-y)=1 (x-y)^2+(x+y)(x-y) 其中 X =3 Y=-1