200X+(20-X)*250+(24-X)*150+(6+X)*180=Y

200X+(20-X)*250+(24-X)*150+(6+X)*180=Y 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 (x-22)+(x-24)+(x-27)+(x-20)=x 用递归法求y=x-(x*x*x/3!)+(x*x*x*x*x/5!)-(x*x*x*x*x*x*x/7!)+. y=(x-1)(x-2)(x-3)(x-4)(x-5)(x-6)(x-7)(x-8)(x-9)(x-10)的导数在x=1 若2x-3y+4=0则x（x*x-1)+x(5-x*x)-6y+7 x+y=20-6 3x+y=30 {(x,y) |x|+|y| x>y?x:y 【2(x-y)^3-8(x-y)^2(x+y)+6y(x-y)^2】/2(x-y)^2=