5x+6y=139 6x+5y=125 这个二元一次方程怎么求?过程要写清楚,标点要清楚,说明为什么要这样算.

(x+y)/6+(x-y)/10=1,(x+y)/6-(x-y)/10=5 {6(x-y)-7(x+y)=21 {2(x-y)-5(x+y)=-1 x+y/2+x-y/6=5 2(x+y)-3(x-y)=-2 6(x-y)-2(x+y)=14 3(x-y)+(x+y)=5 （5x-6y)(x+y)=0(x不等于y),则y/x= 5X+6Y=139 6x+5y=125求X=?y=? 3x+5y-(x+y)=6 2(x+y)-3x=-7 X+Y=5 X*Y=6 求X,Y是多少,就是证明.X+Y=5 X*Y=6 求X,Y是多少, 已知x.x+y.y-6x-8y+25=0,求3x.x+5y的值 把(x-y)看作一个整体,化解:5(x-y)+2(x-y)-4(x-y)= 3(x-y)把(x-y)看作一个整体,化解:5(x-y)+2(x-y)-4(x-y)=3(x-y)²-4(x-y)+7(x-y)-6(x-y)²= y''-5y'+6y=3x+1通解 {x+y=1 ,xy=-6{x(2x-3)=0,y=x²-1{(3x+4y-3)(3x+4y+3)=0,3x+2y=5{(x-y+2)(x+y)=0,x²+y²=8{(x+y)((x+y-1)=0,(x-y)(x-y-1)=0 （x+y-5)*（x+y-5)+（x-y+3)=0 x*x-y*y 已知:3x-5y=0,求x/y,x-y/y,x-y/x 6X+5y=100 x=?y=? {x=5y 3x+6y=42 5x=6y x比y=? x+2y=5x-6y=11