Solving problems with Inequalities

Solving problems with Inequalities

1. Step 1

   • Highlight the important information in this problem. Note: At least is a key word that notes that this problem must be written as an inequality.

2. Example

   • Keith has $500 in a savings account at the beginning of the summer. He wants to have at least $200 in the account by the end of the summer. He withdraws $25 each week for food, clothes, and movie tickets. Write an inequality that represents Keith's situation. How many weeks can Keith withdraw money from his account? Justify your answer.
     • Step 1: Highlight the important information in this problem.
       • Step 2: Identify your variable. What don't you know? The question verifies that you don't know how many weeks. Let w = the number of weeks
         • Step 3: Write your inequality. 500 - 25w > 200
           • How did we get it?
           • Step 4: Solve the inequality
             • How?
             • Step 5: Justify
               • How?

3. Step 3

   • Write your inequality.

4. Step 2

   • Identify your variable. What don't you know?

5. Step 4

   • Solve the inequality.

6. Step 5

   • Justify (prove your answer mathematically).

Images and files in the map