x=1.y=0; x-->(y+x)?10:12.5>y++?'A':'Z'表达式值是多少

（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 x-y/x-x+y/y-(x+y)(x-y)/y² y/x=2 设x大于1,y大于0,x^y+x^-y=2根号二,x^y-x^-y等于? 化简 x / y(x+y) - y / x(x+y) = mathematica软件,已知y[x],Y=f1(x),X(x)=f2(x),如何plot Y[X]?y[x_] := x + 9.81/2*x*xk=1X[x] = x - k*y'[x]/(1 + (y'[x])^2)^0.5Y[x] = y[x] + k/(1 + (y'[x])^2)^0.5Plot[{y[x],Y[X],},{x,0,2}] x(x+y)(x-y)-y(y+x)(y-x)=(x-y)( )填空 x>=1,x-y y=x-1(x y'-(1/x)y=xe^-x 1.(x-y)(x+y)+(x-y)+(x+y)2.x(x+2)-(x+1)(x-1),其中x=-二分之一请写清步骤,结果. y=x(x 若实数x,y满足x-y+1》=0,x+y>=0,x 已知x,y满足约束条件：x-y+1>=0,x+y-2>=0,x 若实数x,y满足x-y+1>=0,x+y>=0,x 画出不等式组x+y>0,x=还有不等式（x-y)(x-y-1)= y'/y=1/x 实数x,y满足{x-y+1>=0;y+1>=0;x+y+1