2-6 Subtraction Equations

Warm Up

Lesson Presentation

Problem of the Day

Lesson Quizzes

2-6 Subtraction Equations

Warm UpSolve 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

2-6 Subtraction Equations

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

2-6 Subtraction Equations

Learn to solve whole-number subtraction equations.

2-6 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?

2-6 Subtraction Equations

Ronald Reagan’s age

Theodore Roosevelt’s age– = 27

Let a represent Ronald Reagan’s age.

a – =27 42

a – 27 = 42

+ 27 + 27

a = 69

Ronald Reagan was 69 years old when he became president.

2-6 Subtraction Equations

y – 23 = 39 23 is subtracted from y.

+ 23

y = 62

Add 23 to both sides to undo the subtraction.

Check y – 23 = 39Substitute 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

2-6 Subtraction Equations

78 = s – 15 15 is subtracted from s.

+ 15

93 = s

Add 15 to both sides to undo the subtraction.

Check 78 = s – 15Substitute 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

2-6 Subtraction Equations

z – 3 = 12 3 is subtracted from z.

+ 3

z = 15

Add 3 to both sides to undo the subtraction.

Check z – 3 = 12Substitute 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

2-6 Subtraction Equations

a – 4 = 7 4 is subtracted from a.+ 4

a = 11

Add 4 to both sides to undo the subtraction.

Check a – 4 = 7Substitute 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

2-6 Subtraction Equations

57 = c – 13 13 is subtracted from c.

+ 13

70 = c

Add 13 to both sides to undo the subtraction.

Check 57 = c – 13Substitute 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

2-6 Subtraction Equations

g – 62 = 14 62 is subtracted from g.

+ 62

g = 76

Add 62 to both sides to undo the subtraction.

Check g – 62 = 14Substitute 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

2-6 Subtraction Equations

Standard Lesson Quiz

Lesson Quizzes

Lesson Quiz for Student Response Systems

2-6 Subtraction Equations

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

2-6 Subtraction Equations

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

2-6 Subtraction Equations

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

2-6 Subtraction Equations

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

2-6 Subtraction Equations

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

2-6 Subtraction Equations

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

2-6 Subtraction Equations

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