Math It s hard to drop, it s hard math

If the length of a coarse candle is L, the length of a thin candle is 2L

In hours, the burning rate of thin candles is 2L, and the burning speed of coarse candles is L 2, and if the power failure time is t, then 2L-2LT=L-(L2)T is solved, and T=2 3 hours, that is, the power outage is 40 minutes.

Assuming the length of a coarse candle is l, then, the length of a thin candle is 2l

Well, a thin candle burns 2l per hour, and a coarse candle burns l 2 per hour

Suppose the power outage is t hours.

Then there is: 2l-2l*t=l-l 2*t

Eliminate l becomes:

2-2t=1-t/2.

3t/2=1.

t=2 3 (hour).

Well, there was a blackout of 2 3 * 60 = 40 minutes.

Solution: Let the coarse candle be long l and the thin candle be 2l long, and it will take x hours for two candles to be the same length.

The burning length of a thin candle per hour is 2l 1, and the burning length of a coarse candle is l 2 per hour, which is solved by the inscription: 2l-2lx 1=l-lx 2 x=2 3 (hours) = 40 (minutes).

A: ......

This is a follow-up question. I'll do it for you with arithmetic, it's easy.

1. Hypothesis: The length of a thick candle is 1. Then, the thin candle is 1 2 2.

2. The burning speed of the thin candle is 2 1 2;Crude candle burns at a rate of 1 2 1 2;

3. Fine candles burn 2 1 2 3 24, (2 1) 3 2 2 3 hours and 40 minutes more per hour than coarse candles.

Solution: Set a power outage for x hours. From the meaning of the title:

2—2x=1—1/2x

Solution: x=2 3

A: Power outage for 2-3 hours.

The unit price was 40 yuan, and the price of celery potatoes was 52 yuan, and 180 were sold. Profit = (52-40) * 180 = 2160 yuan.

Hence the pricing is higher than 52

Yuan. If the sales price is (52+x) yuan, the sales volume will be (180-10x).

52+x-40)*(180-10x)=200012+x)(18-x)=200

216-12x+18x-x^2-200=0x^2+6x+16=0

x^2-6x-16=0

x-8)(x+2)=0

x=-2 (rounded).

x=8 pricing = 52 + 8 = 60 yuan.

Should be restocked = 180-10 * 8 = 100 pcs.

1) The remainder. If the sales price is (52+x) yuan, the sales draft will be (180-10x).

From (52 + x-40) * (180-10x) = 2000 x = 8 pricing = 52 + 8 = 60 yuan.

Should be restocked = 180-10 * 8 = 100 pcs.

2) 150 Sun Jingluo should be purchased, and the price is 55 yuan.

The maximum profit is 2250 yuan.

Solution: (1) If the sales price is (52+x) yuan, the sales volume will be (180-10x).

52+x)(180-10x)-40*(180-10x)=2000 solution. x=8 or x=-2 (rounded).

When the sales price is 60 yuan and the purchase of 100 pieces, the store makes a profit of 2000 yuan.

2) If the sales price is (52+x) yuan, the sales volume will be (180-10x).

52+x)(180-10x)-40*(180-10x)=-10x^2+60x+2160=-10(x-3)^2+2250

When it should be known that 150 pieces of liquid are purchased, the price is 55 yuan.

The maximum profit is 2,250 yuan.

1. On a section of the road, the car and the train depart from the same place, the car departs for 5 hours first, and then the train departs, ask how many hours after the train can catch up with the car?

Solution: 80*1 50=hours.

2. On a 210-kilometer road, the car and the train depart from both ends of the road at the same time, how many hours after the car departs to meet the train?

Solution: 210 (80+50+80)=1 hour.

Mathematics is an important tool subject in primary and secondary schools, and many students have a heavy burden but do not grasp the essentials because they do not have a correct grasp of mathematics learning methods. Some are stuck in a sea of questions, dazed and at a loss.

Therefore, when learning mathematics, we must learn how to master mathematics. Master mathematical skills, develop mathematical ability, and develop good mathematical psychological quality, and form comprehensive learning ability from mastering mathematical learning methods.

Usually you must pay more attention to the method of learning, for the method of learning well can be selectively borrowed but not copied, learn to summarize, you will definitely find your own method, come on!

It's hard to learn, but you can't help it, unless you have other skills.

A good teacher is also important

Elementary school? Secondary school? Or is it from high school?

1+x+ x^2 + x^3 + x^4 + x^5 =(1-x^6)/(1-x)=0

So x=-1

So 1+x+ x 2 + x 3 + x 4 + x 5 + x 6 ·· x 2010=[1-(-1) 2011] (1+1)=1

ps. Use the equal ratio to find the ambush and bury the plum in the late liquid bucket column.

For example, the second group proposes x 6 and becomes x 5 (1+x 2+x 3+x 4) each group carries this because of the clear formula 1+x+ x 2 + x 3 + x 4 + x 5, 2010 6=335, so the original formula is 0

I don't know what age you are, whether it's elementary, middle or high school. But the only shortcut to learning mathematics is: a good head is better than a bad pen, practice more. If you want to learn math well, you must do a lot of problems. But there are also a few aspects to pay attention to.

First of all, learning mathematics should not forget the book, that is, leaving the textbook to make other workbooks, this practice is to abandon the basics and seek the last, which is never advisable. You know, the example problems in the math textbook are more classic than any exercise, if you think that there is a section of the problem is more difficult, then take a good look at this section, before doing the exercise, cover the answer to the example problem, do the example problem yourself, if the example problem can almost be done, it means that you have already thought about it, and then do the exercise, the problem should not be big.

Second, you can't memorize formulas when learning math. If you're doing a post-class question, it's okay to memorize the formula, but it's also about understanding. Nowadays, not only the high school entrance examination, but also the college entrance examination, the mathematics test method is more flexible, so some formulas still require understanding.

So what you need to understand are those parts, that is, there is a process of pushing down in the textbook, and you must figure out how the formula came about, and it is best to be able to push it out yourself.

Again, learning math is not about doing as many problems as possible. Learning mathematics is all about practice, but whenever you see a problem, you must do it yourself, and you can't look at the masters. But it's not that the more questions you do, the better, for example, some questions are very simple, just to test your formula memory, then you can do two or three of these problems, and it is useless to do more.

It is recommended that if you have mastered the basic knowledge, you can look at the interesting competition questions, Olympiad questions, etc., and do some challenging ones (generally this kind of questions are either more comprehensive or more technical). But it doesn't matter if you don't do it, you must remember that the foundation is the most important.

Best, the study of mathematics lies in a thought process. Don't think that everything is good when you get a result, you can discuss with your classmates, there are more than one or two solutions to some problems, and maybe there are easier ways, such as high school geometry. In the process of discussing with classmates or communicating with teachers, you can get a complete idea of how to solve this kind of problem, and you will not be at a loss at all when you encounter this kind of problem.

When Gauss was a child, he meditated on a problem for a night, even if he had the answer, he didn't look at it, and finally solved the problem himself, and this story is about the importance of independent thinking.

In short, whether it is independent thinking or communication and discussion, it is a good habit to do the topic again by yourself at the end. If necessary, it's best to prepare a notebook.,Specifically write down the questions that you think are classics and difficult common mistakes.,After a period of time (ten days and half a month)Take it out and do it yourself.,It's best to take it out and look at it again before the exam.,It's equivalent to reviewing everything that you won't know in the past.,It's much more efficient than reading the whole book.。

That's all for now, if you have any questions to add, welcome to ask, I wish you success in your studies.

Math is certainly not as difficult as being a person!

The charm of mathematics lies in the beauty of numbers.

Whether it is physics, chemistry, biology, or even mechanical manufacturing, the mysteries of the universe are inseparable from mathematics.

Math is difficult due to not finding a good way to learn.

First of all, boost your confidence, overcome difficulties, and think that math is easy to learn, as long as you work hard.

Secondly, make a roll, see where you don't understand, the defect is ** for improvement.

Finally, ask others, teachers, and learn more and ask more questions. You can start with the easy ones and find the resources to learn if you have the difficulties.

Set goals of 50 points, 60 points, 70 points, 80 points... Step by step, and there will definitely be good results in the end.

Assuming that there are x words in the search for trapped materials, and after improving the efficiency, 30 (1+40%)=42 words per minute are typed, and Shinian has.

3/5x÷30-30=3/5x÷42

1/50x-30=1/70x

x=5250

Answer: There are a total of 5,250 words in the Zheng Hall material.