y=-1/3x+2 x=-2 x=-1 x=1 x=2 y 分别等于..

设x>1,y>0,若x^y+x^-y=2根号2,则x^y-x^-y等于 y=(x^2+x)/(x+1) 先化简再求值(x-y)(x+y)-(x-2y) 的完全平方+x(3x-5y)-(x-y)(x-2y),其中x=1/2 y 函数,y=3x/(x^2+x+1) ,x 函数y=3x/(x^2+x+1) （x (3x-y)^2+(3x+y)(3x-y),x=1,y=-2 {3(x+y)-4(x-y)=4 {x+y/2 + x-y/6=1 请问一下,如果y=4x*x*x+3x*x+x+2x+1,怎么用MATLAB实现,x等于多少y 2(x+y) 3x+3y=24 x+y/2x x y/2y= 1 若(x-y)/(x+y)=3 则(x+2y)/(6x-7y)等于 y=x平方+2x+3/x+1(x大于等于-1)的值域 y=(2x*x-2x+3)/(x*x-x+1),求值域?