y=x^2-4x+5.y=-1/4x^2-3/2x+4……的最值和增减性y=x^2-4x+5.y=-1/4x^2-3/2x+4.y=3x^2-2x+1.y=-1/2x^2+2x+1.的最值和增减性期中,把y=-1/2x^2+2x+1的图像画出来.我快没金币了,望谅解.跪谢

{3(x+y)-4(x-y)=4 {x+y/2 + x-y/6=1 (x-y) (x-2y)+(x+2y) (x-3y)-2(x-3y) (x-4y)= x+y+2(-x-y+1)=3(1-y-x)-4-(y+x-1),x+y=? (x-4y)(2x+y)= 先化简 再求值 (2x-y)(y+x)-(x-2y)(2y+x)-(-3y+x)^2其(√x+1)+y^2+4=-4y 已知:【(x²+y²)-(x-y)²+2y(x-y)】/4y=1,求4x/4x²-y²-1/2x+y 化简[(3x+4y)^2-(2x+y)(2x-y)+(-x+y)(5x-y)]除以-2y,其中x=-1,y=1 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 x-y/x-x+y/y-(x+y)(x-y)/y² y/x=2 4x方y/(x-2y)(x+2y)怎么算[x方/x-2y]-4x方y/(x-2y)(x+2y)=? 9y=3x-(x-1),4(x+y)-(2x+4)=8y [(2x-y)^2-y(y-4x)-8x]其中x=-1/2 1.(x-2y)(x+2y)-(x平方+y)(x平方-y) 2.(2x-y)(y+2x)-(2y+x)(2y-x)3.已知：x+y=6,x平方-y平方=48,求x,y的值4.x平方-2x分之x+2 -- x平方-4x+4分之x-1 4x(x-y)-(2x-3y)(2x-3y) x=1 y=-1 [(2x+y)²-y(y+4x)-8x】/4x,其中x=-1,y=2005 急 [(y-2x)(-2x-y)-4(x-2y)²]*2y,其中x=1,y=2 [(y-2x)(-2x-y)+4(x-2y)平方]/3y,其中x=1,y=-3