Embed Size (px)
DESCRIPTION
Transparency 3. Click the mouse button or press the Space Bar to display the answers. Splash Screen. Example 3-3c. Objective. Solve subtraction equations. Example 3-3c. Vocabulary. None. Lesson 3 Contents. Example 1 Solve an Equation by Adding Example 2 Solve a Subtraction Equation - PowerPoint PPT Presentation
Citation preview
Click the mouse button or press the Click the mouse button or press the Space Bar to display the answers.Space Bar to display the answers.
Objective
Solve subtraction equations
Vocabulary
None
Example 1 Solve an Equation by Adding
Example 2 Solve a Subtraction Equation
Example 3 Use an Equation to Solve a Problem
Write the equation.
+ 5
Ask “what is being done to the variable?”
The variable is being subtracted by 5
Do the inverse on each side to “undo” the subtraction
Bring down x - 5
1/3
x – 5
Add 5
= 10
Bring down = 10
Add 5
+ 5
Bring down x
+ 5
1/3
x – 5 = 10 + 5
x
Combine “like” terms
+ 0
Bring down =
=
Combine “like” terms
15Use the Identity Property of Addition to add x + 0
x = 15Answer:
Answer: w = 12
1/3
Write the equation.
x – 5
Ask “what is being done to the variable?”
The variable is being subtracted by 5
Do the inverse on each side to “undo” the subtraction
2/3
Bring down x - 5
= -1
Add 5
+ 5
Bring down = -1
Add 5
+ 5
x – 5
2/3
= -1 + 5 + 5
Bring down x
x
Combine “like” terms
+ 0
Bring down =
=
Combine “like” terms
4Use the Identity Property of Addition to add x + 0
x = 4Answer:
Answer: d = 3
2/3
The difference between the record high and the record low temperatures in Oregon is 173F. The record low temperature is –54F.
Determine process to use
The word “difference” tells us we need to subtract
Difference = high - low
3/3
Replace “difference” with 173
173
Bring down =
What is the record high temperature in degrees Fahrenheit?
Replace “high” with variable
= x
The difference between the record high and the record low temperatures in Oregon is 173F. The record low temperature is –54F.
Difference = high - low
3/3
173
Bring down -
What is the record high temperature in degrees Fahrenheit?
= x - Replace “low” with -54(- 54)
Remember: With 2 negative signs, put them together to make addition
173 = x + 54
Difference = high - low
3/3
173 = x - (- 54)
173 = x + 54
Ask “what is being done to the variable?”
The variable is being added by 54
Do the inverse on each side to “undo” the addition
Bring down 173
173
Subtract 54
- 54
Bring down = x + 54
= x + 54
Subtract 54
- 54
Difference = high - low
3/3
173 = x - (- 54)
173 = x + 54
173 - 54= x + 54 - 54
Combine “like” terms
119
Bring down = x
= x
Combine “like” terms
+ 0
Use the Identity Property of Addition to add x + 0
119 = x
Add dimensional analysis
What is the record high temperature in degrees Fahrenheit?0 F
Answer:
The difference between the age of Julie’s mother and Julie’s age is 27 years. Julie’s age is 6. What is the age of Julie’s mother?
Answer: x = 33 years
*
3/3
NOTE: Could also be 33 years = x
Assignment
Lesson 9:3 Solving Subtraction Equations 12 - 33 All
