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2011-09-20 18:13:00   来源：网络资源    双击单词自动翻译

　　Then we solve:

　　Thus, it takes approximately 22.5 days to reach the 100 pound mark, or, as the question asked, 23 full days.

　　9.　　　E

　　To multiply polynomials two at a time, just distribute the terms of one polynomial into the other one individually:

　　10.　　　C

　　The equation given is in the form of a quadratic equation ax2 + bx + c = 0, so you can use either the reverse FOIL or the quadratic formula to solve for the roots. Before doing either of those things, first factor out 3 from the equation:

　　Factoring takes less time than working out the quadratic formula, so check to see if factoring is possible. It is, and you get:

　　The solution set for x is {1, –9}.

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