题目

已知lga，lgb是方程2x2－4x＋1＝0的两个根，求 lg(ab)·(logab＋logba)的值． 答案： [解] 由题设，得lga＋lgb＝2，lga·lgb＝._______ my job, I had to move to Jinhua. [     ]A. Because of      B. Because       C. With the help of      D. With