问题 填空题

把多项式6a3﹣54a分解因式的结果为  

答案

6a(a+3)(a﹣3)

题目分析:先提取公因式6a,再根据平方差公式进行二次分解.

解:6a3﹣54a=6a(a2﹣9)=6a(a+3)(a﹣3).

故答案为:6a(a+3)(a﹣3).

点评:本题考查了提公因式法,公式法分解因式.注意提取公因式后利用平方差公式进行二次分解,分解要彻底.

单项选择题

The field of medicine has always attracted its share of quacks and charlatans — disreputable women and men with little or no medical knowledge who promise quick cures at cheap prices. The reasons why quackery thrives even in modern times are easy to find.To begin with, pain seems to be a chronic human condition. A person whose body or mind "hurts" will often pay any amount of money for the promise of relief. Second, even the best medical treatment cannot cure all the ills that beset men and women. People who mistrust or dislike the truths that their physicians tell them often turn to more sympathetic ears.Many people lack the training necessary to evaluate medical claims. Given the choice between (a) a reputable physician who says a cure for cancer will be long, expensive and may not work at all, and (b) a salesperson who says that several bottles of a secret formula "snake oil" will cure not only cancer but tuberculosis as well, some individuals will opt for "snake oil".Many "snake oil" remedies are highly laced with alcohol or narcotic drugs. Anyone who drinks them may get so drunk or stoned that they drown their pains in the rising tide of pleasant intoxication. Little wonder that "snake oil" is a popular cure-all for minor aches and hurts! But let there be no misunderstandings. A very few "home remedies" actually work. However, most remedies sold by quacks are not only useless, but often can be harmful as well.

Which of the following would be the best title of this passage

A.Distrust of Physicians

B.Medical Treatment

C.Snake Oil Remedies

D.Guard Against Quackery

单项选择题