x+9y=234 9x+y=366

x+9y=234 9x+y=366 4(x-y)-3(x-y)=9 5(x-y)+2(x-y)=11 y+10x=x+y+9 10y+x=y+10x+27 3(x+y)-2(x-y)=11 4(x+y)+3(x-y)=9 f(x,y)=x*x*x+y*y*y-9xy+27极值 先化简再求值 x(9x-y)-y(y-x)+(x-y)的平方,其中x=-1,y=2 x-y/x-x+y/y-(x+y)(x-y)/y² y/x=2 求函数f（x,y）=x×x×x－y×y×y+3×x×x+3×y×y－9x的极值 化简 x / y(x+y) - y / x(x+y) = 9y=3x-(x-1),4(x+y)-(2x+4)=8y 5x=3y,(2x+y)的平方=5x(x+y)+9 已知y/x=9/10则(1-y/x)[x/(y-x)]? 3y=2x y/3=x/2 12/x=9/y y/x=?y/x=?x/y=? 3x-2y=9 x-3y=2 x+y=5 x+2y=3 y=x 2x+y=8 x>0 y>0 x+y=1,4/X+9/y最小值x>0 y>0 x+y=1,求4/X+9/y最小值 根据3（x+y)-2(x-y)=11,4(x+y)+3(x-y)=9可得出x+y= ,x-y= 先化简在求值:[(x-y)^2 +(x+y) (x-y)]÷2x,其中x=9,y=-1999 设x,y是整数,且x^y=y^x,y=9x,则x的值为