Download Section 4.2a

4.2a – Solving Equations
Variable on one side
Definitions of the Day (DODs)
• Inverse Operation
• Variable
• Expression
• Equation
Definition: Inverse Operations –
Operations that undo each other.
Operation
+
−
×
÷
Inverse Operation
−
+
÷
×
Definition: Variable – A letter or
symbol used to represent a number.
Definition: Expression – A phrase in
math that uses numbers, variables
and operations.
Definition: Equation – A statement
where two expressions are set
equal to each other.
Three Simple Steps to
Equation Solving Success
1.
2.
(leave blank…not needed today)
(leave blank…not needed today)
3. Using inverse operations, move the
variable to one side of the “=” and
everything else to the other side.
SOLVE EACH EQUATION
a) 5 x  2  23
b)
15  25  4 x
Introducing
“Fraction Busters”
A simple way to “deal” with fractions
in equations.
Wanna think?
Then multiply EVERY term in the
equation by the least common denominator of the
fractions
Don’t Wanna think?
Then multiply EVERY term
in the equation by the product of all denominators of the
fractions
SOLVE EACH EQUATION
a)
2
1
x   23
3
5
b)
100
9
 2 x
7
21
Your Turn!!
1. Solve:
a)
45  2 x  95
1
7
b) 12  x  
3
2
Sentence Frames
1.
A variable is a …
____________________________________________
____________________________________________
2.
Inverse operations are operations that … __________
___________________________________________