[(100+140)x]÷2=180（x-2） 二元一次方程,

（X+X)+(X-X)+(X*X)+(X/X)=100 x+x÷3+2x-30=180 x-2x+3x-4x+5x.+99x-100x=25求解 2x+3x+4x+5x+x+6x+7x=100 化简 [3x/(x+2)-x/(x=2)]÷x/(x^2-4)化简 [3x/(x+2)-x/(x-2)]÷x/(x^2-4 (x-2)+(x+2)+(x/2)+(2*x)=180 设f(x)=x+2÷x(x （x-2）×180÷x-360÷x=100 (180x-36*x)/(x+2x)*2x=(180x-36*x)/(x+2x)*x+36x 这个怎么解啊···· (x²-x+1)÷(x²-x-1)=(x²+x)÷(x²+x-2)解方程 X^2-3X-2=0,求( x - 2x-1/x )÷(x-1)/(x^2-2x) 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=100 100(X - 2) + 10X + 2X = 100*2X + 10X + X - 2 - 495 100×2x+10x+3x+216=100×3x+10×2x+x 设函数f(x)=(x-1)(x-2)...(x-100)(x>100),求F'(X)