0.6*0.5*0.3=0.09 cubic meters

The height of brass is x cm.

0.0089 * 20 * 12x = 10.68

x=5

3. If the width is x cm, then

1.2* 1.2= 1.6x

x=0.9

4. Then I'll see you in X hours.

250-50=(40+60)x

x=2

5. Set X minutes to catch up.

75*8+75x= 195x

120x=600

x=5

Besides, show it to your sister.

Listen carefully and do some exercises, and you will sum up the rules. Formulas must remember the etiquette of understanding and learning the following questions, so that mutual assistance can become a kind of happiness and questions can become a knowledge community full of wisdom, warmth and care. 1. Learn to search. When in doubt, please enter the question search first and ask the community for a lot of necessary knowledge for your faster reference. 2. Etiquette of asking questions First of all, the title of the question should be accurate and clear, and the tone of the question should be as objective and friendly as possible to avoid the bad tone of blaming and forcing questions; Secondly, give a necessary and detailed explanation to the question itself, so that others can easily understand it when answering; Thirdly, pay attention to the correct classification of questions in order to get satisfactory answers faster. The etiquette of answering should be to answer other people's questions seriously and accurately, and don't think the questions are too simple. Life is a growing process of "being diligent and inquisitive and supporting each other". 4. Interactive etiquette, self-discipline, respect, sincerity and friendly attitude, treat everyone and every knowledge-sharing inquiry. After asking questions, we should deal with them in time and respect the labor achievements of others. Thanks to all the netizens who answered their questions, please also give some friendly comments to the respondents, "Give someone a rose and leave a lingering fragrance in your hand". Reciting formulas is the most basic. Many fill-in-the-blank questions can be worked out as long as you know the formula. I'm not good at math either, but I always recite some formulas before exams. When the exam comes, even if you can't write the formula, you will get points. Formulas are very helpful to fill in the blanks. You can try! ! ! ! ! Learning is an important part of learning. Whether the review method is appropriate or not determines the quality of review and directly affects the learning effect and examination results. So how can we do a good review? First, the process of consolidating basic review is the advanced stage of mastering knowledge. The quality of review depends on mastering the basic knowledge. Therefore, when learning new knowledge, we should "slowly and steadily" and "step by step" at a normal pace to lay a good foundation. We should fully understand and master the basic concepts, laws and methods. You must not learn new knowledge with a little knowledge, and "swallow the dates" and become "raw food". I hope to make up for it when reviewing, and set obstacles for mastering the knowledge in an all-round way. Second, at the beginning of self-study induction review, first carry out unit reading study according to the textbook, systematically review, summarize and take notes. Generally, the contents of induction are: 1. What basic concepts and laws have you learned in this unit? 2. Find out the connections and differences between knowledge points, list knowledge networks, write outlines or draw charts; 3. The key points, difficulties, doubts, points for attention, test sites and hot spots of this unit; How did you master the experiment in this unit? 5. What knowledge is not mastered or well mastered in this unit? Third, when checking for leaks and filling vacancies, on the basis of their own induction, compare with the teacher's comprehensive and systematic summary. Find out the gap and analyze the reasons, so as to improve their inductive power, further strengthen their understanding of knowledge, understand the problems that have not been clarified, and thoroughly understand and master all the basic knowledge. Through the above two links, it is mainly to link the scattered, individual and isolated knowledge learned before and turn it into systematic knowledge, thus making a qualitative leap in understanding and mastering knowledge. Fourth, trying to figure out the examples in the textbook and the examples explained by the teacher are generally typical and representative. We should study hard, understand deeply, learn to use what we have learned, analyze and solve problems flexibly through "models", especially learn how to analyze and solve problems, and sum up the laws of solving problems. In this way, we can draw inferences from others. Fifth, don't engage in "sea tactics" when reviewing intensive exercises. Under the guidance of teachers, we should choose a high-quality reference book, improve our thinking ability and problem-solving skills through solving problems, and deepen our understanding of what we have learned. When solving problems, we should think independently, think about one more problem, solve one more problem, ponder over it repeatedly and realize the truth. We should be good at finding our own shortcomings in solving problems and finding out the root causes to enrich them; We should be good at summarizing the law of solving problems and improving the ability of solving problems. In this way, we can take one as ten, and win more with less. Sixth, summarize and improve the follow-up test after review. The purpose is to check the review effect and cultivate students' ability to take exams. So take it seriously. On the basis of the teacher's analysis of the test paper, self-summary, mainly summarizing the thinking method and learning method, finding out the problems and deficiencies in learning, and making clear the direction of future efforts. For those who don't like mathematics, mathematics is a very boring subject, but for those who like mathematics, it is a happy tree. Whenever I do a topic, I will feel a sense of accomplishment. You must do it slowly and have fun while doing it. If you have fun, you will naturally be interested.