2009 Tianjin Question 1 Single-choice Differentiating 2009_天津 Paper 1.i是虚数单位, $\frac { 5 i } { 2 - i } =$ A. $1 + 2 i$B. -1-2iC. 1−2iD. $- 1 + 2 i$ Answer keyD ☆ SaveCan't do it, show the explanation查看原卷 →