6x=3x-7 5=7+2x y-1/2=1/2y-2 11/9x+2/7=2/9x-5/7

y=(x-1)(x-2)(x-3)(x-4)(x-5)(x-6)(x-7)(x-8)(x-9)(x-10)的导数在x=1 若2x-3y+4=0则x（x*x-1)+x(5-x*x)-6y+7 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 3x+2=y 5X+4=Y 7X+6=Y 9X+8=y 11x=y要如何计算 3x+2=y 5x+4=y 7x+6=y 9x+8=y 11x=y y-3x=2,y-5x=4,y-7x=6,y-9x=8,y-11x=0方程组, 3x+2=y 5x+4=y 7x+6=y 9x+8=y 11x=y 联立方程 有的话 有几道题想请教一下7x=6x-4 x-15=74 3x=2x+5 -5x=8-4x 9y=6y-6 8x=4x+1 7x (1){x+2y=0,3x+4y=6(2){5x+6y=16,7x-9y=5（3）{9x-11y+1=0,4x-5y-3 解方程组(x+y)(x-2y)=-5 (x-y)(x+2y)=7 5x-(1-11y)/8=5y-6x+2/9=3x+4y+7/6 若(x-y)/(x+y)=3 则(x+2y)/(6x-7y)等于