x+5.5x=13

x+5.5x=13怎么解? （X+X)+(X-X)+(X*X)+(X/X)=100 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 13x-x=24 1.1x+2.2=5.5-3.3x 6-5x=3/4-4x [给金币, 若x=π/3,｜x+1|+|x+3|+...+|x+13|-|x+2|-|x+4|-...-|x+12| x+x=x+15