Download Objectives: SWBAT evaluate algebraic expressions

Objectives: SWBAT evaluate algebraic expressions
Anchors: M8.D.2 - Represent and/or analyze mathematical situations using numbers,
symbols, words, tables and/or graphs.
1-1:
Variables and Expressions
Coefficient
Variable
Key Terms:
1. Variable - a letter that represents a value that can change or vary.
2. Coefficient - the number multiplied by the variable.
3. Algebraic Expression – expression that has one or more variables. Ex: x+6
4. Constant – value that does not change. ex: x+6
5. Evaluate – to find the value of a numerical or algebraic expression
6. Substitute – to replace the variable with a value or another expression
EX1: Evaluating Algebraic Expressions with One Variable
Evaluate each expression for the given value of the variable.
A
B
x + 6 for x = 13
13 + 6 Substitute 13 for x.
19 Add.
2a + 3 for a= 4
2(4) + 3 Substitute 4 for a.
8+3
Multiply.
11
Add.
EX2: Evaluating Algebraic Expressions with Two Variables
2x + 3y for x = 15 and y = 12
2(15) + 3(12)
Substitute 15 for x and 12 for y.
30 + 36
Multiply.
66
Add.
1.5p - 2q for p = 18 and q = 7.5
1.5(18) - 2(7.5)
Substitute 18 for p and 7.5 for q.
27 - 15
Multiply.
12
Subtract.
Think and Discuss
1. Give an example of an expression that is algebraic and of an expression that is not algebraic.
2. Tell the steps for evaluating an algebraic expression for a given value.
3. Explain why you cannot find a numerical value for the expression 4x - 5y for x= 3.
{Homework: pg 6 #s 10-30 all)