Warm Up Problem of the Day Lesson Presentation Lesson Quizzes

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

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

Learn to solve whole-number subtraction equations.

When Theodore Roosevelt became president of the United States, he was 42 years old. He was 27 years younger than Ronald Reagan was when Reagan became president. How old was Reagan when he became president?

= = – – Let a represent Ronald Reagan’s age. Ronald Reagan’s age 27 Theodore Roosevelt’s age – = – = a 27 42 a – 27 = 42 + 27 + 27 a = 69 Ronald Reagan was 69 years old when he became president.

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

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

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

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

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

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

Lesson Quizzes Standard Lesson Quiz Lesson Quiz for Student Response Systems

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

Lesson Quiz for Student Response Systems 1. Solve the equation x – 17 = 36. A. x = 19 B. x = 21 C. x = 36 D. x = 53

Lesson Quiz for Student Response Systems 2. Solve the equation 20 = x – 6. A. x = 14 B. x = 20 C. x = 26 D. x = 40

Lesson Quiz for Student Response Systems 3. Solve the equation y – 16 = 33. A. y = 59 B. y = 49 C. y = 23 D. y = 17

Lesson Quiz for Student Response Systems 4. Solve the equation 52 = y – 23. A. y = 29 B. y = 31 C. y = 75 D. y = 84

Lesson Quiz for Student Response Systems 5. Solve the equation x – 15 = 22. A. x = 43 B. x = 37 C. x = 13 D. x = 7

Lesson Quiz for Student Response Systems 6. During an NBA playoff game, Brand scored 12 points more than Cassell. If Cassell had 33 points how many points did Brand score? A. 45 points B. 33 points C. 21 points D. 12 points