Two charges lie on the $x$ axis, a $-2.00-\mu$ C charge at the origin and a $+3.00-\mu \mathrm{C}$ charge at $\mathrm{x}=0.100 \mathrm{~m} x=0.100 \mathrm{~m}$. At what position along the $x$ axis, if any, should a third $+4.00-\mu \mathrm{C}$ charge be placed so that the net force on the third charge is equal to zero? Example $16-3$