3x^2-7x-6 怎么算

(x+2)(x+3)-(x+6)(x-1) 怎么算? x^2-6x+9/x^2-x-6 * x^2-7x+10/x^2-9 * x+3/2(x-5)怎么算? x^8+x^7+x^6+x^5+x^4+x^3+x^2+x+1怎么分解因式 x(7-8x)=3(x-2) 怎么算 (X-3)/(X^2-4)*(X^2-4X+4)/(x^2-x-6)-1/(x+2)怎么算?(X-3)/(X^2-4)*(X^2-4X+4)/(x^2-x-6)-1/(x+2),怎么算? *-----------------------------------------------*| 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 || 1+x+x^2+x^3+x^4+x^5+x^6+x^7+x^8+x^9+x^10+x^11+x^12=97.8x+x^2+x^3+x^4+x^5+x^6+x^7+x^8+x^9+x^10+x^11+x^12=97.8 好多年没有用过过数学公式了 想不起来怎么算了 想知道 X值是多少 x-1+x-2+x-3+x-4+x-5+x-6+x-7=77怎么解速度! 3x^2-7x-6 怎么算 (x-3)/2=x/7+6怎么算 1/(x+1)(x+2)+1/(x+3)(x+4)+1/(x+5)(x+6)+1/(x+7)(x+8)+1/(x+9)(x+10)怎么解 (x^4-6x^2+x+7)/(x^2+x-2)怎么算! 7x(x-6)+3x=4x(2x+5)怎么解这个方程 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^2-x-60怎么算x^2-x-6 (x-1)(x+2)(x+3)(x+6)怎么做? (x^10-x^5+1)/(x^2+x+1) 怎么算?(x^10-x^5+1)/(x^2+x+1)=（x^8-x^7+x^5-x^4+x^3-x+1) (2x-1)(2x+1)+3(x+2)(x-2)=(7x-1)(x+1)怎么算?