x-1=2x+4 求x 2x-4y=3x 求x与y的比

求值域 1,y=(x+2)/(x*x+3x+6) 2,y=3x/(x*x+4) 一个“整式的乘法”的问题请先阅读下列解题过程,再仿做下面的问题.已知X*X + X - 1=0,求X*X*X + 2*X*X + 3的值.解X*X*X + 2X*X +3=X*X*X +X*X -X +X*X +X +3=X{X*X +X -1} +X*X +X -1 +4=0+0+4=4+ x + X*X + X*X*X=0.+ X*X + X*X*X x(x+1)+(x+2)+(x+3)+(x+4)+(x+5) = 27求x 求y=x^-4x+3/2x^-x-1的值域y=（x^2-4x+3）/（2x^2-x-1） 求函数y=(3x+4)/(x-2) (x 求y=(5x-1)/(4x+2) (x x²-4x-1=0,求(2x-3)²-(x+y)(x-y)-y² 已知x-y=1,求[(x+2y)^2+(2x+y)(x-4y)-3(x+y)(x-y)]除以y的值大神们帮帮忙 已知x-y=1,求[(x+2y)²+(2x+y)(x-4y)-3(x+y)(x-y)]÷y的值 y=(2x*x-2x+3)/(x*x-x+1),求值域? 若2x-3y+4=0则x（x*x-1)+x(5-x*x)-6y+7 已知2y-x=-3,求[4y(2x-y)-2x(2x-y)]/(2x-y 求值域 y=(x²-2)/(x²+x+1); y=2x-3+√(13-4x); y=(3x+2)/(x-1) 求值域 y=(x²-1)/(x²+x+1); y=2x-3+√(13-4x); y=(3x+2)/(x-1) y=x/3x+1,x属于[2,4] 求值域x属于(2,4] 求函数y=3x^2+3x+4/x^2+x+1的最大值 y=(3x^2+3x+4)/(x^2+x+1)求最大值 y=(x-x^3)/(1+2x^2+x^4)的最大最小值怎么求?