x+x=y x-x=y x乘以x=y x除以x=y x的数字必须一样,四个y加起来等于100 考你算术

x-y/x-x+y/y-(x+y)(x-y)/y² y/x=2 y=x(x 化简 x / y(x+y) - y / x(x+y) = x(x+y)(x-y)-y(y+x)(y-x)=(x-y)( )填空 y=|x|/x乘以2^x的单调性 y=|x|/x乘以2^x的单调性 x+x+x+x+y+y+y=56 (x+y)9次方乘以（x+y）= [(x/x-y) -1]/(y的平方/x+y)乘以(x-x的平方/x+y),其中x=—2,y=—1. 推倒公式:(x+y)(x*x-3x+y*y)=x*x*x+y*y*y怎么做. （xy-x^2)乘以(xy)/(x-y)= x(y-x)乘以（xy）/(x-y)= -x(x-y)乘以（xy）/(x-y)= -x^2y这样做对吗? x+x+x+y+y=6.4 y+y+y+x+x=7.1 怎么算? 二元函数f(x,y)=x+y/x-y,求f(y/x,x/y) x-y/x+y=(x-y)²/x²-y²（x≠y) （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 已知x=2+根号3,y=2-根号3,计算代数式(x+y/x-y-x-y/x+y)乘以(1/x^2-1/y^2) x+x+x+y=60 .x-y=4