2(x+y)-3(x-y) =1 6(x+y)+7(x-y)=51大神们帮帮忙

2(x+y)-3(x-y) =1 6(x+y)+7(x-y)=51大神们帮帮忙 求导y=(x+1)(x+2)(x+3)(x+4)的导数大神们帮帮忙 若3(X-Y)=2(X+Y),且X不等于0,则X/Y+Y/X的值为多少大神们帮帮忙 2(x+y)-3(x-y)=1 6(x+y)+7(x-y)=51 解方程组 解方程组﹛2(x+y)-3(x-y)=1 6(x+y)+7(x-y)=51 若(x-y)/(x+y)=3 则(x+2y)/(6x-7y)等于 {3(x+y)-4(x-y)=4 {x+y/2 + x-y/6=1 求y=1/x-3 +x (x＞3）的最小值大神们帮帮忙 求Y=2X+4X-7/X+2X+3的值域大神们帮帮忙 【2(x-y)^3-8(x-y)^2(x+y)+6y(x-y)^2】/2(x-y)^2= 若x、y满足2x+y=6,x-3y=1,求7y(x-3y)²-2(3y-x)³的值 x+y=3 x+2y=9 3/x+1=y y-x=3 y=2x-3 y-3x=1 2(x+1)-y=6 7x-5y=-9