Algebraic Expressions and Equations

Algebraic Expressions and Equations

Topics in this review:

1. Expressions vs. Equations

2. One-Step Equations

3. Two-Step Equations

4. Modeling Equations

Expressions vs. Equations

• Expressions: numbers, letters, and operators grouped together to represent a value

• NO = SIGN , CANNOT ALWAYS SOLVE!

• Equations: states that two expressions are equal

• HAS = SIGN, CAN SOLVE FOR THE VARIABLE!

Multiple Choice

Which of the following is an equation?

• $-17+9$
  

• $-17+9=-8$
  

Multiple Choice

Pick out the expression.

• 
  

   $5x+4-9=22$  

•  $25=-5x$ 
  

•  $4a-3c+15-12a$  

•  $6\left(x-3\right)=52$  

Multiple Choice

Which of the following is not an equation?

• 2x+5=12

• 5+12

• 5m-8=24

• -8=x-9

Multiple Choice

 $4m-7+8m-17$  True or False: I can solve an algebraic expression like the one below and get an answer like x=#.

• True

• False

FALSE

Algebraic expressions cannot be solved! You can only simplify them (combine like terms or use distributive property). You should never get an answer of x=# with algrebaic expressions.

One-Step Equations

• GOAL: GET VARIABLE BY ITSELF!

• To do this: get rid of the number on the same side of the equation as the varibale by using inverse operations!

Two-Step Equations

• GOAL: GET VARIABLE BY ITSELF!

• First step: Get rid of the constant using the inverse operation

• Second step: Get rid of the coefficient using the inverse operation