Eleven forces each equal to 5N act on a particle simultaneously. If each force makes an angle ${30}^0$ with the next one, the resultant of all forces is (2x+1) then x is ______

12 equal forces at an angle 30⁰ with the next one will form a polygon and according to polygon law of vectors, their resultant will be zero. 

$\Rightarrow \overrightarrow{F_1}+\overrightarrow{F_2}......\overrightarrow{F_{12}}=0$

$\Rightarrow \overrightarrow{{\mathrm{F}}_1}+\overrightarrow{{\mathrm{F}}_2}...\overrightarrow{{\mathrm{F}}_{11}}=-\overrightarrow{{\mathrm{F}}_{12}}$

The magnitude will be 

$\left|\overrightarrow{{\mathrm{F}}_{12}}\right|=5\mathrm{N}$