2x-5y=1 2y-5x=8怎么解2x-5y=1 2y-5x=8二元一次方程组···怎么解 过程?

3x+2=y 5x+4=y 7x+6=y 9x+8=y 11x=y怎么解 X+y=15 2x-y=5y-x怎么解 二元二次方程(x+y)(x-2y)=-5,(x-y)(x+2y)=7 怎么解 y-x/7-x+y/6=1/2 5(x+y)-2(y-x)=1怎么解答 {2X=5(X+Y)3X-10(X+Y)=2怎么解? 3x*5y+2x*6y=2.7*(3x+2x)怎么解 X+Y=5.7 1/4X+2/5Y=4/5X 怎么解 解方程组(x+y)(x-2y)=-5 (x-y)(x+2y)=7 {6(x-y)-7(x+y)=21 {2(x-y)-5(x+y)=-1 (x-y)/(x+y)=3求( 3x-2y-1)/(x+y-5) 解方程组 2x-y=5 2y/x-x/y=12x-y=52y/x-x/y=1 x+y=1 5x-2y=8 3x-y=7 2x-y=3x表示y和用y表示x 已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y) (x/y)2-(x/y)=1怎么解? {(x+y)/2+(x-y)/3=1,(x+y)-5(x-y)=2.求x=?,y=? x-y/x-x+y/y-(x+y)(x-y)/y² y/x=2 3 x+5y =8和2x-y=1这个方程组怎么解 {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