25x X 5 +15x X 10 +12x X 15 =7280

1x+2x+3x+4x+5x+6x+7x+8x+9x+10x+11x+12x+13x+14x+15x=550 (2x^-5x+2/6x^+13x+6)*(6x^-5x-6/6x^-17x+10)*(12x^+8x-15/2x^-x X/15 + X/12 + X/10 = 1365,求X, x+x=x+15 (x+12)(x-2)+(x+7)(x+8)-(x+5)(x-10),其中x=2 化简|x-5|+|x+10|-|x-15|, 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 (25/X)X(30/X)= 15/X怎么算 （X+X)+(X-X)+(X*X)+(X/X)=100 5x/64-x/25=15 x是多少 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!)+. (5X-15)-(2X+3)=X+12