Cho \[{z_1} = 2 + i;\,\,{z_2} = 1 - 3i.\]. Tính \[A = {\left| \right|^2} + {\left| \right|^2}.\]

Ta có:\(\left\{ {\begin{array}{*{20}{c}}{{z_1} = 2 + i}\\{{z_2} = 1 - 3i}\end{array}} \right. \Rightarrow \left\{ {\begin{array}{*{20}{c}}{|{z_1}{|^2} = {2^2} + 1 = 5}\\{|{z_2}{|^2} = 1 + {{( - 3)}^2} = 10}\end{array} \Rightarrow {{\left| \right|}^2} + {{\left| \right|}^2} = 15.} \right.\)

Đáp án cần chọn là: D