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