In order to solve this problem, we need to know the requirements of the topic. The title requires us to find three numbers on three lines, so that the sum of these three numbers is equal to 90.
The list of known numbers is: 10, 20, 30, 40, 50, 60, 70, 80, 90.
Traverse this list and find three numbers that meet the requirements.
The three numbers in the first line are: 10, 20, 30, which adds up to 60.
The three numbers in the second line are: 40, 50 and 60, which add up to 150.
The three numbers in the third line are: 70, 80 and 90, which add up to 240.
Check whether each sum is equal to 90. If they are all equal to 90, then the answer is correct; Otherwise, the answer is wrong.
The sum of three numbers in each row is not equal to 90, and the answer is wrong.
Ways to learn mathematics well:
1. Make a study plan: Make a detailed study plan according to individual study goals and timetable, and stick to it. This will help to allocate time reasonably and ensure that there is enough time to study mathematics every day.
2. Understand the basics: To learn mathematics well, you need to master the basic concepts and formulas of mathematics. Therefore, we should listen carefully, understand the meaning and application of mathematical concepts, and master basic formulas skillfully.
3. Exercise topics: Through a large number of exercise topics, we can deepen our understanding of mathematical concepts and master problem-solving skills. You can try different types of questions, such as multiple-choice questions, fill-in-the-blank questions, and calculation questions. Improve your problem-solving ability and thinking flexibility.
4. Understand the problem: before solving the problem, understand the meaning and purpose of the problem. This helps to find the solution to the problem quickly and accurately.
5. Cooperate with others: You can discuss math problems with your classmates, help each other and make progress together.
6. Ask for help: You can ask your teacher or classmates for help when you encounter problems. Don't be afraid to ask questions, because it helps to better understand the problem and get new ideas and methods.