{3x-5y=-2{2x+7y=40上面那个是个大括号来的

{3x-5y=-2{2x+7y=40上面那个是个大括号来的 方程组：第一题（5+1）x=5y 第二题x-y/3=x+y/2 4y-4x=30+10 2x-3y=7（5+1）x=5y x-y/3=x+y/2 4y-4x=30+10 2x-5y=7 上面那个题目错的 方程组{上面的4x+3y=17下面2x+5y=19 1:4(x-100)+3y=5 2:6(x-y)-2(x+y )=14 x-100=-y 3(x-y)+(x+y)=5 先无视上面的1.4(x-100)+3y=5x-100=-y2.6(x-y)-2(x+y )=143(x-y)+(x+y)=5 已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y) 1、x+y=300,x=y+10.2、x-3y=1,x+2y=6.求上面这两道题中x、y的值, 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 解二元一次方程组上面3x+2y=5,下面2x+5y=7 用代入法解方程组：y+x x+2y=4 x-7y=0 x+2y=4 ｛y+4x=15 ｛2x-3y=1 ｛x-9y+8=0 ｛x+y=5效率.1,｛y+x x+2y=4 2,｛x+2y=4 2x-3y=1 3,｛x-7y=0 x-9y+8=0 4,｛x-y=3 x+y=5 上面打错了 x-y/x-x+y/y-(x+y)(x-y)/y² y/x=2 3x+5y-(x+y)=6 2(x+y)-3x=-7 x+y=1 5x-2y=8 3x-y=7 2x-y=3x表示y和用y表示x 求这几道二元一次方程的解,直接是x,y等于多少就行,1.3x-2y=1 x-y=3 2.x+3y=-5 3x-4y=-2这个是接着上面的.3.y-3x=2x-2y=34.5x+3y=22x-y=35.3x-y=42x+y=66.2x+3y=73x-2y=3 x+y/3+x-y/2=6 4(x+y)-2(x-y)=40 解方程组(x+y)(x-2y)=-5 (x-y)(x+2y)=7 x+y/2+x-y/6=5 2(x+y)-3(x-y)=-2 {6(x-y)-7(x+y)=21 {2(x-y)-5(x+y)=-1 3(x+y)+2(x-y)=36 4(x+y)-5(x-y)=2