x/150+y/200+(3000-x-y)/240=31 (3000-x-y)/150+y/200+x/240=31,解方程

x/150+y/200+(3000-x-y)/240=31 (3000-x-y)/150+y/200+x/240=31,解方程 二元一次方程帮忙解下(1)12.5x+13.3y-200=12x+13.5y12.9x+13.9y-1300=12.5x+13.3y x=?y=?(2)200x+150y=5500150x+100y=4000 x=?y=?(3)x+y=68100x+y-100y-x=2178 x=?y=? {(x,y) |x|+|y| x>y?x:y x^/y-x-y^/y-x化简. 化简x(y-x)-y(x-y) 行列式计算 x y x+y y x+y x x+y x y|x y x+y ||y x+y x ||x+y x y | y/(x+y)-x/(x-y) 150X+140Y≤3000 (1) X≤Y (2) 3X+2Y=50 (3) 怎样解 X+Y+Z=300 X+Z=200 Y+Z=150 求X Y Z 分别为多少. 因式分解x(x+y)(x-y)-x(x+y)^2 x(x+y)(x-y)-x(x+y)的平方 x(x+y)(x-y)-x(x+y)² 因式分解 x-y/x-x+y/y-(x+y)(x-y)/y² y/x=2 x-y=80,x+x-y=200,x等于多少,y等于多少? x y x+yy x+y xx+y x y (3x-y)(3y+x)-(x-y)(x+y) 化简x/y(x+y)-y/x(x+y)