3x-/x+15/

x(x*x-6x-9)-x(x*x-8x-15)+2x(3-x) 3x-/x+15/ 通分:x+4/x^2-8x+15,x-5/x^2+x-12,x-3/x^2-x-20 X(x平方-6x-9)-x(x平方-8x-15)+2x(3-x)其中x=-六分之一 3X+30+X+X-15=? 13x-15x+x=-3 3x-x(10-x)=15 [(x+2)/(x+3)-(x+1)/(x+2)+(x+4)/(x+5)-(x+3)/(x+4)]/[(x的平方+7x+13)/(x的平方+8x+15)] 计算:[(x+2)/(x+3) - (x+1)/(x+2) + (x+4)/(x+5) - (x+3)/(x+4) / (x^2 + 7x + 13)/(x^2 + 8x + 15) (x-1)(x+1)(x+3)(x+5)+15 (x-1)(x+1)(x+3)(x+5)+15 因式分解 (x+1)(x+3)(x+5)(x+7)+15 (x+1)（x+3)(x+5)(x+7)+15因式分解 因式分解1+x+x^2+x^3+```+x^15 (x+1)(x+2)(x+3)(x+4)-15 (x^21+x^15+x^12+x^9+x^6+x^3+1)/(x^2+x+1) 证明(x+1)(X+3)(x+5)(x+7)+15=(X+8x)+22(x+8x)+120 x^3+x-30(分解因式);x^12-y^12;x^15+x^14+x^13.x^2+x+1