(i) z1+z2z_1+z_2z1+z2 z1=−922−922i,z2=52+532iz_1=-\frac{9\sqrt{2}}{2}-\frac{9\sqrt{2}}{2}i,\quad z_2=\frac{5}{2}+\frac{5\sqrt{3}}{2}iz1=−292−292i,z2=25+253i z1+z2=5−922+53−922i\boxed{z_1+z_2=\frac{5-9\sqrt{2}}{2}+\frac{5\sqrt{3}-9\sqrt{2}}{2}i}z1+z2=25−92+253−92i