Big Ideas Ch 3 Expression and
Equations
3. 1 Algebraic Expressions
How are they different?
Expression
• No =
• Can only simplify
Equation
• Has an =
• Solve for missing variable
Give an Numerical Expression:
3 +4
Give a Numerical Equation
3+4 = 7
Give an Algebraic Expressions
3x+4
Give an Algebraic Equation
3x +4 =7
Your brother tries to tell you that
6x +4 -2x is the same thing as 8x+4.
• Is it?
• No!!!
• Explain why your brother’s answer is
incorrect.
• It is incorrect because 6x -2x =4x not 8x
• What is the correct answer?
• The correct answer is 4x +4
• How did you get the correct answer?
Terms
• After you turn all subtraction into addition
using (KFC) terms are what is separated by
addition signs
Like Terms
• Terms that have the same variables raised to
the same exponent
Simplest Form
• Algebraic expressions are in the simplest form
when it has not like terms and no
parentheses.
Combine Like Terms
• If terms are alike, then you have add or
subtract the coefficients (number in front of
the variable) and keep the variable to its
exponent.
simplify
14- 3z +8 +z
14+ (-3z) +8 + 1z
-3z +1z +14+8
-2 z +22
Distributive Property
• If there are parentheses and a number on the
outside of the () distribute the number
through the () then collect like terms
simplify
-2 (g +4) +7g
-2(g) +-2(4) +7g
-2g +(-8) +7g
-2g +7g +(-8)
5g +(-8)
Simplify
3
1
7  4( x  )
4
4
3
1
7  4[ x  (  )]
4
4
3
1
7  (4)( x)  (4)( )
4
4
7  ( 3 x )  1
3x  8
Homework
• Big Ideas Text Book Page 84 (1-20, 24) all