1. Lesson 2-5 2 Days Equations and Problem Solving Pages 103 - 110

2. Objective The learner will solve real-life problems writing one unknown in terms of another

3. Some problems contain two or more unknown quantities. To solve such problems, first decide which unknown quantity the variable will represent. Then express the other unknown quantity or quantities in terms of that variable.

4. The length of a rectangle is 6in. more than its width. The perimeter of the rectangle is 24in. What is the length of the rectangle? Define: Let w be the width. Then w + 6 = length. Write: P =2l + 2w 24 = 2(w+6) + 2w (substitute) Distribute & Solve

5. Now you try: The width of a rectangle is 2cm less than its length. The perimeter of the rectangle is 16cm. What is the length of the rectangle?

6. Now you try: The length of a rectangle is 8 cm more than twice the width. The perimeter of the rectangle is 34 cm. What is the length of the rectangle? What is the area of the rectangle?

7. Practice 2-5 Page 28 in workbook # 4, # 5, # 13, # 14

8. Consecutive Integers differ by 1. The integers 50 and 51 are consecutive. So are -10, -9, and -8. For consecutive integer problems, it may help to define a variable before describing the problem in words. Let a variable represent one of the unknown integers. Then define the other unknown integers in terms of the first one.

9. The sum of three consecutive integers is 147. Find the integers. Restate: 1 st integer plus 2 nd integer plus 3 rd integer equals 147. Illustrate: Let n be the first integer. Let n + 1 be the second integer. Let n + 2 be the third integer. n + n + 1 + n + 2 = 147 Calculate & Examine

10. The sum of three consecutive integers is 48. a. define a variable for one of the integers b. write expressions for the other two integers c. write and solve an equation to find the three integers. d. check your answer

11. Now you try: The sum of four consecutive even integers is 308. Write and solve an equation to find the four integers. The sum of three consecutive odd integers is -87. What are the integers?

12. Practice 2-5 Page 28 in workbook # 11, # 12