【X+1/2]+【2y-1】=0,则x+y=多少

若x+y=1,x不等于0则x+(2xy+y^2)/x/(x+y)/x= 若2x-3y+4=0则x（x*x-1)+x(5-x*x)-6y+7 若y=x(x-1)(x-2)(x-3),则y′（0）= 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}] 设x大于1,y大于0,x^y+x^-y=2根号二,x^y-x^-y等于? 若x,y满足|x-y+1|+(x+y+3)^2=0则x^2-y^2= 若x,y满足|2x-y-3|+|3x+2y+1|=0,则x= y= 已知(x+y)^2-2x+2y+1=0,则(x+y)^999= 若|x+y+1|+(x-2y)的平方=0,则x+2y=? 如果|x-2y+1|+|2x-y-5|=0,则x+y=? |2x+y+1|+√2y+3x=0则x.y= 已知x+y=1,x>0,y>0,则2x+y/xy等于 |x-2y+1|+(x+y-5)²=0,则5x+4y= 已知（x+y)²-2（x+y）+1=0,则x+y=? (x+y)²-2(x+y)+1=0则x+y= 已知x属于R,y>0,集合A={x|x*x+x+1,-x,-x-1},集合B={-y,-y/2,y+1}若A=B,则x*x+y*y的值为 y=1-x^2 x>=0 ,y=sin|x|/x x 已知x,y满足约束条件：x-y+1>=0,x+y-2>=0,x