X+Y=5,x-y=8,求x,y

已知:3x-5y=0,求x/y,x-y/y,x-y/x 已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y) 已知：4x = 5y,求(x+y) ：y 已知x.x+y.y-6x-8y+25=0,求3x.x+5y的值 已知x-y=8,（x+y)(x-y)=32,求x,y的值 求(X+Y)(X-Y)(X²+Y²),X=5 Y=2, X+Y-8X+10Y+41=O,求X/Y-Y/X的值 (x-y)/(x+y)=3求( 3x-2y-1)/(x+y-5) 二元函数f(x,y)=x+y/x-y,求f(y/x,x/y) y=x^3-5x^2+2x-8 求y^2求y撇 求y'=y/(y-x) x+y+|x-y|=-56 求x*y 最小值 x^y=y^x,求dy. {(x+y)/2+(x-y)/3=1,(x+y)-5(x-y)=2.求x=?,y=? |x|=3 |y|=5 |x-y|=|x|+|y| 求 X+Y和 X-Y 等于多少 已知X*X+Y*Y+6X-8Y+25=0 求（Y/X)+(X/Y)-2=? 已知x+y=-5,x*x+y*y=19求xy和（x-y)*(x-y)的值 x*x+2x-y*y+6y-8=0,x+y不等于2,求x-y的值