"Practical problems and linear inequalities of one variable" Inequalities and Inequality Groups PPT Courseware 5

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"Practical problems and linear inequalities of one variable" Inequalities and Inequality Groups PPT Courseware 5

Self-learning

1. What are the properties of inequalities? What are the similarities and differences between it and the properties of equations?

2. What are the steps to solve a linear equation of one variable? What about solving linear inequalities of one variable?

3. What is the key to solving word problems using linear inequalities of one variable?

Xiaolan plans to spend 30 yuan to buy pens and notebooks. It is known that a pen costs 4.5 yuan and a notebook costs 3 yuan.

(1) If she buys 5 notebooks, how many more pens can she buy at most?

(2) If she buys 8 pens and notebooks in total, how many pens can she buy at most?

Analysis: pen cost + notebook cost ≤ 30

Solution: Suppose he can also buy x pens. According to the meaning of the question, we get

4.5x+3×5≤30

Solve to get x≤10/3

∵X is an integer,

∴X=3

Answer: He can buy up to 3 pens.

Solution: Suppose he can buy x pens, then the number of notebooks is (8-x). According to the meaning of the question, we get

4.5x+3(8-x)≤30

Solve for x≤4

∴X=4

Answer: He can buy up to 4 pens.

Practice expansion

A certain unit wants to produce a batch of promotional materials. Advertising Company A proposes to charge 50 yuan for each material, plus a design fee of 2,000 yuan. Advertising Company B proposes to charge 70 yuan for each material, with no design fee.

(1) Under what circumstances is it more cost-effective to choose Company A?

(2) Under what circumstances is it more cost-effective to choose Company B?

(3) Under what circumstances will the charges of the two companies be the same?

Keywords: Teaching courseware for inequalities and groups of inequalities, teaching courseware for practical problems and linear inequalities of one variable, PPT courseware for the second volume of seventh-grade mathematics published by the New People's Education Press, downloading of seventh-grade mathematics slide courseware, downloading PPT courseware for inequalities and groups of inequalities, practical problems and Download PPT courseware of linear inequalities of one variable in .ppt format

For more information about the PPT courseware "Inequalities and Groups of Inequalities, Practical Problems and Inequality of the First Degree in One Variable", please click on the Inequality and Group of Inequality ppt Practical Problems and Inequality of the First Degree in One Variable ppt tag.

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Update Time: 2024-09-28

This template belongs to Mathematics courseware People's Education Press Seventh Grade Mathematics Volume 2 industry PPT template

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