有7x+2x=140 9.3x+5.7x=4.5 6x+3x=180 7x-5x=16 7.8x-2.4x=1.08 5.8x+9.2x=72 25x+35x=460 跪谢

有7x+2x=140 9.3x+5.7x=4.5 6x+3x=180 7x-5x=16 7.8x-2.4x=1.08 5.8x+9.2x=72 25x+35x=460 跪谢 x/x-2+x-9/x-7=x+1/x-1+x-8/x-6, x/x-2+x-9/x-7=x+1/x-1+x-8/x-6, *-----------------------------------------------*| 6 4 X | 8 X X | X X 5 || X X X | X X X | X 7 8 || X X X | X X X | X X X ||---------------+---------------+--------------- || X X X | X X X | 5 1 X || X X X | X 6 X | X X X || 8 X X | 3 5 X | 2 X X || x+2x+3x+4x+5x+6x+7x+8x+9x=9x-8x-7x-6x-5x-4x-3x-2x-x.x等于多少? 填九宫格帮帮忙.x x 6 x x 7 x x 98 x x x 3 x 1 x x 9 x x 6 x 5 x 3 x x x 3 x x x x 1 8x x x 9 x 1 x x x2 1 x x x x 6 x x x 6 x 7 x 3 x x 1 x x 9 x 2 x x x 47 x x 8 x x 5 x x (x+12)(x-2)+(x+7)(x+8)-(x+5)(x-10),其中x=2 2x+3x+4x+5x+x+6x+7x=100 x+2/x+1-x+4/x+3=x+6/x+5-x+8/x+7 x=? 设f(x)=x(2x-1)(x+3)(x-7),则f'(x)=0有几个正根 (x+1)/(x+2)+(x+8)/(x+9)解答x+1/x+2+x+8/x+9=x+2/x+3+x+7/x+8 f(x)=x^2+x (x 用递归法求y=x-(x*x*x/3!)+(x*x*x*x*x/5!)-(x*x*x*x*x*x*x/7!)+. （X+X)+(X-X)+(X*X)+(X/X)=100 分解因式x^7+x^5+x^4+x^3+x^2+1原式=（x^7+x^4)+(x^5+x^2)+(x^3+1)=x^4(x^3+1)+x^2(x^3+1)+(x^3+1)=(x^3+1)(x^4+x^2+1)问问有没有化简完 7x^2-5x=2x^2+x x-2/3x+x+2/7x=30 27046=2x( )+7x( )+4x( )+6x( )