4x+9x=13x
X+13%X-28%X=3.
x+13%x-28%x=3.4
13x-6.3x+x=46.8 x=多少
解方程((13x-x^2)/(x+1))(x+(13-x)/(x+1))=42
(13x-x^2)/(x+1)[x+(13-x)/(x+1)]=42
1x+2x+3x+4x+5x+6x+7x+8x+9x+10x+11x+12x+13x+14x+15x=550
(X+X)+(X-X)+(X*X)+(X/X)=100
若x=π/3,|x+1|+|x+3|+...+|x+13|-|x+2|-|x+4|-...-|x+12|
18.1-X=13怎么解方程?
已知2x*x+x-5=0,求代数式6x*x*x+7x*x-13x+11的值
解方程(x+1)(x+3)+4x=-13