1. 2-6 Subtraction Equations Course 1 2-6 Subtraction Equations Course 1 Warm Up Warm Up Lesson Presentation Lesson Presentation Problem of the Day Problem of the Day

2. 2-6 Subtraction Equations Course 1 Warm Up Solve each equation. 1. x + 7 = 22 2. 18 + x = 105 3. 16 = x + 9 4. 23 = x + 4 x = 15 x = 87 x = 7 x = 19

3. 2-6 Subtraction Equations Course 1 Problem of the Day Bruce has 25 CDs remaining after giving 14 to John, 17 to Mary, and 25 to Sue. How many CDs did he begin with? 81

4. 2-6 Subtraction Equations Course 1 Learn to solve whole-number subtraction equations.

5. 2-6 Subtraction Equations Course 1 When John F. Kennedy became president of the United States, he was 43 years old, which was 8 years younger than Abraham Lincoln was when Lincoln became President. How old was Lincoln when he became president?

6. 2-6 Subtraction Equations Course 1 Abraham Lincoln’s age John F. Kennedy’s age – = 8 Let a represent Abraham Lincoln’s age. a – = 843 a – 8 = 43 + 8 a = 51 Abraham Lincoln was 51 years old when he became president.

7. 2-6 Subtraction Equations Course 1 y – 23 = 39 23 is subtracted from y. + 23 y = 62 Add 23 to both sides to undo the subtraction. Check y – 23 = 39 Substitute 62 for y in the equation. Solve y – 23 = 39. Check your answer. 62 is the solution. 39 = 39 ? Additional Example 1A: Solving Subtraction Equations 62 – 23 = 39 ? + 23

8. 2-6 Subtraction Equations Course 1 78 = s – 15 15 is subtracted from s. + 15 93 = s Add 15 to both sides to undo the subtraction. Check 78 = s – 15 Substitute 93 for s in the equation. Solve 78 = s – 15. Check your answer. 93 is the solution. 78 = 78 ? Additional Example 1B: Solving Subtraction Equations 78 = 93 – 15 ? + 15

9. 2-6 Subtraction Equations Course 1 z – 3 = 12 3 is subtracted from z. + 3 z = 15 Add 3 to both sides to undo the subtraction. Check z – 3 = 12 Substitute 15 for z in the equation. Solve z – 3 = 12. Check your answer. 15 is the solution. 12 = 12 ? Additional Example 1C: Solving Subtraction Equations 15 – 3 = 12 ? + 3

10. 2-6 Subtraction Equations Course 1 a – 4 = 7 4 is subtracted from a. + 4 a = 11 Add 4 to both sides to undo the subtraction. Check a – 4 = 7 Substitute 11 for a in the equation. Solve a – 4 = 7. Check your answer. 11 is the solution. 7 = 7 ? 11 – 4 = 7 ? + 4 Check It Out: Example 1A

11. 2-6 Subtraction Equations Course 1 57 = c – 13 13 is subtracted from c. + 13 70 = c Add 13 to both sides to undo the subtraction. Check 57 = c – 13 Substitute 70 for c in the equation. Solve 57 = c – 13. Check your answer. 70 is the solution. 57 = 57 ? 57 = 70 – 13 ? + 13 Check It Out: Example 1B

12. 2-6 Subtraction Equations Course 1 g – 62 = 14 62 is subtracted from g. + 62 g = 76 Add 62 to both sides to undo the subtraction. Check g – 62 = 14 Substitute 76 for g in the equation. Solve g – 62 = 14. Check your answer. 76 is the solution. 14 = 14 ? 76 – 62 = 14 ? + 62 Check It Out: Example 1C

13. 2-6 Subtraction Equations Course 1 1. x – 9 = 21 2. 14 = x – 3 3. x – 7 = 11 4. 16 = x – 14 5. x – 9 = 11 Lesson Quiz 6. Susan is taller than James. The difference in their height is 4 inches. James is 62 inches tall. How tall is Susan? x = 30 x = 17 x = 18 x = 30 x = 20 66 inches