(i) z1+z2z_1+z_2z1+z2 z1=7(6+2)4−7(6−2)4iz_1=\frac{7(\sqrt{6}+\sqrt{2})}{4}-\frac{7(\sqrt{6}-\sqrt{2})}{4}iz1=47(6+2)−47(6−2)i z2=−11(6+2)4+11(6−2)4iz_2=-\frac{11(\sqrt{6}+\sqrt{2})}{4}+\frac{11(\sqrt{6}-\sqrt{2})}{4}iz2=−411(6+2)+411(6−2)i z1+z2=−(6+2)+(6−2)i\boxed{z_1+z_2=-(\sqrt{6}+\sqrt{2})+(\sqrt{6}-\sqrt{2})i}z1+z2=−(6+2)+(6−2)i