Câu 16: Phương trình $2 \cos \left(2 x-20^{\circ}\right)+\sqrt{3}=0$ có nghiệm là: A. $\left[\begin{array}{c}x=170^{\circ}+k 360^{\circ} \\ x=-130^{\circ}+k 360^0\end{array}(k \in \mathbb{Z})\right.$. B. $\left[\begin{array}{c}x=85^{\circ}+k 180^{\circ} \\ x=-65^0+k 180^{\circ}\end{array}(k \in \mathbb{Z})\right.$. C. $\left[\begin{array}{l}x=85^0+k 360^{\circ} \\ x=25^0+k 360^{\circ}\end{array}(k \in \mathbb{Z})\right.$. D. $\left[\begin{array}{l}x=85^0+k 180^0 \\ x=25^{\circ}+k 180^{\circ}\end{array}(k \in \mathbb{Z})\right.$.