x+y=300 5%x+53%y=25%*3003x+4y-2.9=0 5x-2y-0.5=0解方程！

（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 x-y/x-x+y/y-(x+y)(x-y)/y² y/x=2 x+y=5; x^y+y^x=17 已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y) 若(X×X+Y×Y)(X×X+Y×Y-5)=36,则X×X+Y×Y＝ 化简 x / y(x+y) - y / x(x+y) = (X-Y)(X+Y)=5 能解么 5x-4y(y-x)=? x(x+y)(x-y)-y(y+x)(y-x)=(x-y)( )填空 y-x=x-5 x+x+y+y+y=21 ,x+x+y+y+y+y+y=27 ,x ,y=? x+x+y+y+y=21 ,x+x+y+y+y+y+y=27 ,x ,y=? 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 y=x(x Y={X (-5 Y={X (-5 2(x-y)=5y,x-y=-5