题干

香港违法“占中”行动对香港的经济、政治、社会及民生造成重大损失,据香港科技大学经济系教授雷鼎鸣测算,仅香港的“占中”行动开始后一个多月的时间,保守估计造成经济损失3500亿港元,相等于平均每名港人承受了5万港元的损失,为了挽回经济损失,某厂家拟在新年举行大型的促销活动,经测算某产品当促销费用为x万元时,销售量t万件满足t=5﹣
2
x
+
1
(其中0≤x≤a2﹣3a+3,a为正常数).现假定生产量与销售量相等,已知生产该产品t万件还需投入成本(10+2t)万元(不含促销费用),产品的销售价格定为(4+20
t
)万元/万件.
(1)将该产品的利润y万元表示为促销费用x万元的函数;
(2)促销费用投入多少万元时,厂家的利润最大.
上一题 下一题 0.0难度 选择题 更新时间:2019-04-17 07:42:35

答案(点此获取答案解析)

解:(1)由题意知,该产品售价为2×(10
+
2
t
t
)万元,y=2×(10+2

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    Communicating with elderly parents is an important part of making sure they're doing okay.____

    It's important to set aside time every week to call up or drop by and see how your parents are doing.____Also listen for the things they're not telling you, such as health problems or money worries.

    Your parents might be slower and less active than before.____It's important to respect this. Don't think that your elderly parents can't take care of their needs unless there are clear signs that this is the case. Remember, your elderly parents always care about being treated as someone who matters.

    ____ Also you must keep your words simple and often ask your elderly parents whether they've really understood. If you realize your parents need to make a major change, like moving to a nursing home, talk about such future issues early in small steps. Ask them about their plans for the future and what they hope. When you get a feel for what they prefer, you can slowly mention the topic of starting to make such changes.

    Accepting the generation gap (代沟) is also important.____For most people, making changes to their lifestyles, their opinions and their beliefs gets much harder as they age. Your views might differ a lot, but it's best to agree to disagree.

A. Bring happiness into your parents' life.

B. Be clear when you explain anything to your parents.

C. However, they're still able to make their own decisions.

D. Know their daily happenings and ask them what they're doing.

E. Though life is busy, remember to stay in touch with your parents.

F. Your parents have been doing things a certain way for a long time.

G. Be prepared to find suitable advisers that your parents might need.