2012 Tianjin Question 1 Single-choice Differentiating 2012_天津卷 (2012·理) 1.i是虚数单位,复数 $\dfrac{7-i}{3+i}=$ A. 2 + iB. 2 - iC. -2 + iD. -2 - i Answer keyB ☆ SaveCan't do it, show the explanation查看原卷 →