Solving OneStep Equations

1
Solving One-Step Equations
By Mrs. DePasquale
2
Definitions to Know

• Variable

- a letter that stands for a number
Constant
- an integer by itself
Opposite Operation
- add opposite subtract - multiply opposite
divide
3
Opposite Operations
Solve mentally.
Solve pencil paper arithmetic.
X 2 5
X 3
X 67.8 134.5
X 66.7
X 11
X 3 8
X 16.72 51.3
X 68.02
2X 8
X 4
3.4X 21.6
X 9
X/27 135
X 5
X/3 7
X 21
4
Algebraic Method
ADDITION
Goal Isolate the variable
X 4 10
-4 -4
Take 4 away from both sides of the equation
X
0
6
Rename Simplify
X
Rename Simplify
6
Check Plug in answer
X 4 10
6
4 10
Rename Simplify
10
10
5
Algebraic Method
SUBTRACTION
Goal Isolate the variable
X - 4 10
4 4
Add 4 to both sides of the equation
X
0
14
Rename Simplify
X
14
Rename Simplify
Check Plug in answer
X 4 10
14
- 4 10
Rename Simplify
10
10
6
Algebraic Method
MULTIPLICATION
Goal Isolate the variable
3X 12
Divide both sides by 3
/3 /3
X
4
Rename Simplify
Check Plug in answer
3X 12
34
Rename Simplify
12
12
12
7
Algebraic Method
DIVISION
Goal Isolate the variable
X /4 8
4 4
Multiply both sides of the equation by 4
X
32
Rename Simplify
Check Plug in answer
X/ 4 32
32
/4 8
Rename Simplify
8
8
8
TRY IT OUT
Solve Use algebraic method
X 7 15
I.
II.
III.
IV.
X 2 13
4x 24
X/12 12
2 2
-7 -7
12 12
/4 /4
X 15
X 8
X 6
X 144
Check Use algebraic method
IV.
X/12 12
I.
X 7 15
II.
X 2 13
III.
4x 24
7 7 15
15 2 13
46 24
144/12 12
24 24
15 15
13 13
12 12
9
Tips and Tricks

• Algebra Balance

• Perform same operation on both sides

• Always rename on one side at a time

• Plug in variable in original equation

10
Next Steps
For more practice at home see Mrs. D.s Quia
Quizzes http//quia.com/pages/mary1853.html To
view this lesson at home see Mrs. D.s Math
Class http//sms8math.homestead.com/mathmain.html