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Câu hỏi: Cho ${{z}_{1}}=3-2i,{{z}_{2}}=4+5i$. Tính ${{z}_{1}}+{{z}_{2}}$.
A. ${{z}_{1}}+{{z}_{2}}=7-7i$.
B. ${{z}_{1}}+{{z}_{2}}=1+7i$.
C. ${{z}_{1}}+{{z}_{2}}=7+3i$.
D. ${{z}_{1}}+{{z}_{2}}=12-10i$.
A. ${{z}_{1}}+{{z}_{2}}=7-7i$.
B. ${{z}_{1}}+{{z}_{2}}=1+7i$.
C. ${{z}_{1}}+{{z}_{2}}=7+3i$.
D. ${{z}_{1}}+{{z}_{2}}=12-10i$.
${{z}_{1}}+{{z}_{2}}=\left( 3-2i \right)+\left( 4+5i \right)=\left( 3+4 \right)+\left( -2+5 \right)i=7+3i$.
Đáp án C.
