2x+(99-x)×(1÷2)=99怎样解 有赏

2x+(99-x)×(1÷2)=99怎样解 有赏 x/(x-2)+(x+9)/(x-7)=(x+1)/(x-1)+(x-8)/(x-6)怎样解这道方程 怎样解-x^2+2x=1/x 小数奥数网xx(x +1)x(x+ 2)x(x +3)=360怎样算? 1/X(X+1)+1/(X+1)(X+2)+1/(X+2)(X+3).+1/(X+99)(X+100)= 解方程：2x+4x+6x...+100x=1-(x+3x+5x+...+99x) 1X+2X+3X…+98X+99X+100X=50500X X等于多少? 1x+2x+3x+4x+5x+6x+7x…+99x=100 f(x)=x(x-1)(x-2)…(x-99)(x-100),求f'(100) x(x-1)(x-2)...(x-99)(x-100) y=x^x的导函数是：y'=x^x(Inx+1)我知道怎样求.但为什么不可以这样求.y=x^x=x*x*x*x*x*x*...*x(x个x) 则y'=(x')*x^(x-1)+x*(x')*x^(x-2)+.=x^x 2x=x+7怎样解 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 2x(2x+5)=(x-1)(2x+5)怎样算? F(X+1)=F(-X+1)怎样得到F(X)=F(2-X) x-1分之x+1 减 x+1分之3X-3 = 2 怎样计算 怎样由f(x+2)=1/f(x)得出f(x+4)=f(x) f(x)=ln(x^3+3x^2+3x+1)怎样化简