则有 360=6X+15Y 440=8X+10Y X= 50,Y=4 即 每节火车皮装 50吨,为啥X=50 Y=4 你

{3(x+y)-4(x-y)=4 {x+y/2 + x-y/6=1 x+y/2+x-y/3=6,4(x+y)-3(x-y)=-20 {(x+y)/2+(x-y)/3=6 4(x+y)-3(x-y)=-20 4(x+y)-3(x-y)=-20,2/x+y+3/x-y=6 ｛4/(x+y)+6/(x-y)=3 ｛9/(x-y)-1/(x+y)=1 (4x-2y-z)-{5x[8y-2y-(x+y)]-x+(3y-10z)]=? kuai 已知2x-y=10,求[(x²+y²)-(x-y)²+2y(x-y)]/4y 解方程组 10（x-y)=3(x+y)+15 6(x+y)=4(2x-y)+16 已知x*x+4x+y*y-2y+5=0,则x*x+y*y=? [(x+2y)(x-2y)-(x-2y)^2+8y(x+y)]除以4x= 已知x的平方+y的平方-8x+6y+25=0,求(x-y+4xy/x-y)(x+y-4xy/x+y) 已知x²+y²-8x+6y+25=0,求（x-y+4xy/x-y）（x+y-4xy/x+y）