3x^2-x=1求6x^3+7x^2-5x+1990.的值

*-----------------------------------------------*| 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 || 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 求一个数独答案X X X 9 X X X 8 2 X 6 3 X X 1 4 X 99 X 8 X X X X X XX X X 6 7 X 3 X XX 4 6 X 5 X 2 9 XX X 7 X 2 3 X X XX X X X X X 7 X 17 X 4 3 X X 6 2 X6 3 X X X 7 X X X (x-1)(x-2)(x-3)(x-4)=(x+5)(x+6)(x+7)求X等于几? 如果1+x+x^2+x^3=0,求x+x^2+X^3+x^4+x^5+x^6+x^7+x^8的值, 已知x=2π+1求 |x-1|+|x-2|+|x-3|+|x-4|+|x-5|+|x-6|+|x-7|+|x-8|+|x-9|+|x-10| 已知x=2π+1.求(X-1)+(X-2)+(X-3)+(X-4)+(X-5)+(X-6)+(X-7)+(X-8)+(X-9)+(X-10) 1X?+2X?+3X?+4X?+5X?+6X?+7X?+8X?+9X?+10X?=1980求?是多少 若3x^2-x=1,求6x^3+7x-5x+2009 已知1+x+x^2+x^3=0,求x+x^2+x^3+x^4+x^+x^6+x^7+x^8的值 7x-6+5x+1=4x+3-2x求x是多少 x(x+1)+(x+2)+(x+3)+(x+4)+(x+5) = 27求x x+2/x+1-x+4/x+3=x+6/x+5-x+8/x+7 x=? 解一道初一的分式方程（x+1)/(x+2)+(x+6)/(x+7)=(x+2)/(x+3)+(x+5)/(x+6)求x的值 已知3x*x-x=1,求6x*x*x+7x*x-5x+2000 若x*x+x+1+0,求x^7+2x^6+x^5+x^4+x^3+x*x+1的值 1.(x*2-3x+3)/(x*2-3x+2)-(x*2-5x+7)/(x*2-5x+6)-1/(x*2-4x+3)2.1/x(x+1)+2/(x+1)(x+3)+3/(x+3)(x+6) 3.已知：x*2-3x+1=0,求x*2+1/x*2. (x+2)(x-1)+(x+3)(x+1)=x·x-1 求x (5x-4)(2x+5)(3x-6)(2x-4)=(2x-4)(2x+5)·0.5 求x