2/3x+1/6x＝15

(x^21+x^15+x^12+x^9+x^6+x^3+1)/(x^2+x+1) 1x+2x+3x+4x+5x+6x+7x+8x+9x+10x+11x+12x+13x+14x+15x=550 已知 X=4- 根号3 求 (X*X*X*X-6X*X*X-2X*X+18X+23) / (X*X-8X+15)的值 |X-1|+|X-2|+|X-3|+|X-4|+|X-5|+|X-6|+|X-7|+|X-8|+|X-9|+|X-10| 解方程x/(x-2)=2x/(x-3)+(1-x)/(x-5x+6) 将[(X+3/X^2-4)-(-X/6-X-X^2)]/[1-(X^2-3X-15)/(X^2+X-6)]化简 X(X的2次方-6X-9)-X(X的2次方-8X-15)+2X(3-X),其中X=1/3. 先化简,再求值 x+2/x^2-x-6 + 2x/x^3-3x - x+1/x^2-6x+9 (x+2/x^2-x-6)-(2x/x^2-3x)-(x+1/x^2-6x+9) (x+1-1/1-x)÷(x-x²/x-1) (x-4/x-x-6+ x+2/x-3)÷x+1/x-3 x/(x-1) -1＝3/(x-1)(x+2) (x-6)×(x-3) (x+2/1)×(x-3/1)