\text { This question concerns two complex numbers, } \mathrm{z}_{1}=A-B i \text { and } \mathrm{z}_{2}=-C+D i \text {. } \text { (a) Plot the numbers } z_{1} \text {

and } z_{2} \text { on the same Argand diagram. } \text { (b) Find } z_{3}=2 z_{1}+3 z_{2} \text {. } (d) Show that the locus of points z = x + iy in the complex plane that satisfythe equation |z – z1| = |z + z2| lie on a straight line. Write down the slope and intercept of the straight line. \text { Find } z_{4}=z_{1} z_{2} \text { and express } z_{4} \text { in exponential form as } z_{4}=r e^{i \theta}