1. Warm Up
Problem of the Day
Lesson Presentation
Lesson Quizzes

2. Warm Up
Solve.
1. x – 15 = 9
2. x + 21 = 34
3. 17 = x – 11
4. 22 = x – 34
x = 24
x = 13
x = 28
x = 56

3. Problem of the Day
If a newborn baby weighs two pounds plus three-fourths its own weight, how much does it weigh?
8 pounds

4. Learn to solve equations by adding and subtracting fractions.

5. Additional Example 1A: Solving Equations by Adding and Subtracting
Solve each equation. Write the solution in simplest form. 3 5 __
x = 14 3 5 __
x = 14
Subtract from both sides to undo addition. 3 5 __ 3 5 __ 3 5 __
– – 5
______ ______ 5 __ 3 5 __
Regroup 14 as 5 __
x = – 5 2 5 __
x = 8
Subtract.

6. Additional Example 1B: Solving Equations by Adding and Subtracting
Solve each equation. Write the solution in simplest form. 2 9 __ 1 3 __
3 = x – 4 2 9 __ 1 3 __
3 = x – 4
Add to both sides to undo the
subtraction. 1 3 __ 1 3 __ 1 3 __
______ ________ 2 9 __ 3 9 __
= x
Find a common denominator. 5 9 __
7 = x
Add.

7. Additional Example 1C: Solving Equations by Adding and Subtracting
Solve each equation. Write the solution in simplest form. 1 6 __ 7 12 __
6 = m + 1 6 __ 7 12 __
6 = m + 7 12 __ 7 12 __ 7 12 __
Subtract from both sides to undo the
addition.
– –
______ ______ 2 12 __ 7 12 __
6 – = m
Find a common denominator. 14 12 __ 7 12 __ 2 12 __ 12 __ 2 12 __
5 – = m
Regroup as 7 12 __
5 = m
Subtract.

8. Additional Example 1D: Solving Equations by Adding and Subtracting
Solve each equation. Write the solution in simplest form. 4 5 __ 3 10 __
w – = 3 4 5 __ 3 10 __
w – = 3 4 5 __ 4 5 __ 4 5 __
Add to both sides to undo subtraction.
_____ _____ 3 10 __ 4 5 __
w =
Find a common denominator. 3 10 __ 8 10 __
w =
Add. 11 10 __ 1 10 __ 11 10 __
w = 3
Regroup = 3 + 1 1 10 __
w = 4

9. Check It Out: Example 1A
Solve each equation. Write the solution in simplest form. 5 8 __
x = 12 5 8 __
x = 12
Subtract from both sides to undo addition. 5 8 __ 5 8 __ 5 8 __
– – 3
______ ______ 8 __ 5 8 __
Regroup 12 as 8 __
x = – 3 3 8 __
x = 8
Subtract.

10. Check It Out: Example 1B
Solve each equation. Write the solution in simplest form. 3 8 __ 1 4 __
2 = x – 3 3 8 __ 1 4 __
2 = x – 3 1 4 __ 1 4 __
Add to both sides to undo the
subtraction. 1 4 __
______ ______ 3 8 __ 2 8 __
= x
Find a common denominator. 5 8 __
5 = x
Add.

11. Solve each equation. Write the solution in simplest form.
Check It Out: Example 1C
Solve each equation. Write the solution in simplest form. 2 5 __ 7 10 __
5 = m + 2 5 __ 7 10 __
5 = m + 7 10 __ 7 10 __ 7 10 __
Subtract from both sides to undo the
addition.
– –
______ ______ 4 10 __ 7 10 __
5 – = m
Find a common denominator. 14 10 __ 7 10 __ 4 10 __ 10 __ 4 10 __
4 – = m
Regroup as 7 10 __
4 = m
Subtract.

12. Solve each equation. Write the solution in simplest form.
Check It Out: Example 1D
Solve each equation. Write the solution in simplest form. 1 3 __ 5 6 __
w – = 5 1 3 __ 5 6 __
w – = 5 1 3 __ 1 3 __ 1 3 __
Add to both sides to undo subtraction.
_____ _____ 5 6 __ 1 3 __
w =
Find a common denominator. 5 6 __ 2 6 __
w =
Add. 7 6 __ 1 6 __ 7 6 __
w = 5
Regroup = 5 + 1 1 6 __
w = 6

13. Additional Example 2: Application1 4 __
Linda’s dog weighs pounds. If Linda’s dog weighs pounds less than Ian’s dog, how much does Ian’s dog weigh? 1 2 __ 1 2 __ 1 4 __
d – = 85
Let d represent the weight of Ian’s dog. 1 2 __ 1 2 __ 1 2 __
Add to both sides to undo the
subtraction.
________ ________ 3 4 __
d = 102

14. Additional Example 2 Continued
Check 1 2 __ 1 4 __
d – = 85 3 4 __ 1 2 __ ? 1 4 __ 3 4 __
– = 85
Substitute for d. 3 4 __ 2 4 __ ? 1 4 __
– = 85
Find a common denominator. 3 4 __ 1 4 __ ? 1 4 __
85 = 85
is the solution. 3 4 __
Ian’s dog weighs pounds.

15. Check It Out: Example 2 2 3 __
Jimmy’s cat weighs pounds. If Jimmy’s cat weighs
4 pounds less than Vicki’s cat, how much does Vicki’s
cat weigh? 1 6 __ 1 6 __ 2 3 __
c – = 13
Let c represent the weight of Vicki’s cat. 1 6 __ 1 6 __ 1 6 __
Add to both sides to undo the
subtraction.
_______ ________ 5 6 __
c = 17

16. Check It Out: Example 2 Continued1 6 __ 2 3 __
c – 4 = 13 5 6 __ 1 6 __ ? 2 3 __ 5 6 __
– 4 = 13
Substitute for c. 5 6 __ 1 6 __ ? 4 6 __
– 4 = 13
Find a common denominator. 5 6 __ 4 6 __ ? 4 6 __
13 = 13
is the solution. 5 6 __
Vicki’s cat weighs pounds.

17. Lesson Quizzes
Standard Lesson Quiz
Lesson Quiz for Student Response Systems

18. Lesson Quiz Solve each equation. Write the solution in simplest form.
1. x – 3 = x = 11
= x – = x –
5. Marco needs to work 40 hours per week. He has worked hours so far this week. How many hours does he need to work on Friday to meet his 40-hour requirement? 3 4 __ 5 12 __
x = 6 1 6 __ 5 8 __
x = 4 3 8 __ 7 10 __
x = 4 1 2 __ 4 3 4 __ 1 2 __
x = 6 1 4 __ __ 5 5 8 __ 3 8 __
hours

19. Lesson Quiz for Student Response Systems
1. Solve the equation and identify the solution in simplest form. A. C. B. D.

20. Lesson Quiz for Student Response Systems
2. Solve the equation and identify the solution in simplest form. A. C. B. D.

21. Lesson Quiz for Student Response Systems
3. Solve the equation and identify the solution in simplest form. A. C. B. D.

22. Lesson Quiz for Student Response Systems
4. Solve the equation and identify the solution in simplest form. A. C. B. D.

23. Lesson Quiz for Student Response Systems
5. Jim needs to work 35 hours to complete his project. He has worked hours so far. How
many hours more does he have to work to complete the project? A. C. B. D.