42/x+y=2,42/x-y=14解

x-y/x-x+y/y-(x+y)(x-y)/y² y/x=2 {80/(x+y) +42/(x-y) =7 40/(x+y) +70/(x-y) =7 怎么解( ⊙ o ⊙ {80/(x+y) +42/(x-y) =7 40/(x+y) +70/(x-y) =7 快 急 6(x-y)-2(x+y)=14 3(x-y)+(x+y)=5 解方程组(x+y)(x-2y)=-5 (x-y)(x+2y)=7 42/x+y=2,42/x-y=14解 解方程：2(x+y)=42 ① 14(y-x)=42 ② 解方程组80/x+y + 42/x-y=7 40/x+y + 7/x-y=7非常感谢! x+y=11 2x+4y=42 3y+x=31 求x y 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 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 解方程组 4(x+y)-(2x-y)=14 ,3(x+y)-2(2x-y)=8 解方程组 (x+y)^2-3(x+y)=54 (x-y)^2-5(x-y)=14 请解答方程组：（39）2x+y=5 (40)x+y=7 (41)2x+3y=12 (42)2x+y=3ax+3y=7 2x-y=8 3x+4y=17 3x-5y=11(43)3x+y=82 (44)3(x-1)=y+5 45 x/4+y/3=7 (46)x+y/3 +x-y/2=610x-11y=87 5(y-1)=3(x+5) 2/3x+y/2=14 3(x+y-)2(x-y)=28 解方程组4（x+y)-3(x-y)=14;(x+y)/2+(x+y)/3=6 若X+Y=6,X^2-Y^2=42,则X-Y=? x+x+x+y=42 x+y+y+y=30 求x=( )y=( ) ｛x/60+y/80=10,x/60+y/40=15、｛2x/3+3y/4=1/5,5x/6-5y/2=2、｛5/2(x+y）=1200,10/3（x+y）=1200｛4x+5y=98,5y-4x=2、｛x/3+y/4=54/60,y/4+x/5=42/60怎么解?{40-y=x-4 40-y=y-x 由X/Y=2Y/X-Y 怎么解得x=2y?