An \(x y z\) coordinate system contains three charged particles: particle \(1, q_{1}=-5.0 \mu \mathrm{C}\), at \((4.0 \mathrm{~m},-2.0 \mathrm{~m}, 0)\); particle \(2, q_{2}=12 \mu \mathrm{C}\), at \((1.0 \mathrm{~m}, 2. 0 \mathrm{~m}, 0)\); and an electron at \((-1.0 \mathrm{~m}, 0,0)\).

(a) Draw a diagram showing the vectors you need in order to determine the direction of the separate electric forces exerted on the electron by particles 1 and 2.

(b) Calculate the vector sum of these two forces.