2011 Zhejiang Question 3 Single-choice Differentiating 2011_浙江卷 (2011·文) 3.(5分)(2011•浙江)若实数x,y满足不等式组 ,则3x+4y的最小值是( ) A. 13B. 15C. 20D. 28 Answer keyA ☆ SaveCan't do it, show the explanation查看原卷 →