Download 2-1 Evaluating and Writing Algebraic Expressions

January 11, 2016
2-1 Evaluating and Writing
Algebraic Expressions
• To write and evaluate algebraic expressions
Warm Up Skills
1. The set of rules for simplifying an expression is called the ______________.
2. 3 + 4 ● 2
3. 12 - 6 ÷ 3
4. 6 ● (5 - 7) + 2
5. (4 + 3) ● 2 - 11
January 11, 2016
Key Vocabulary
Variable: a letter or symbol used to represent one or more numbers.
Algebraic Expression: a mathematical phrase with at least one variable.
Word Phrase
a temperature of t degrees
increased by 5 degrees
five cats fewer than c cats
the product of 5 and n
nickels
Diagram
Algebraic Expression
t+5
c-5
January 11, 2016
Writing Algebraic Expressions
1. Write an algebraic expression for each word phrase.
a. swimming m meters per minute for 3 minutes
b. 12 heartbeats more than x heartbeats
Your turn ...
1. Write an algebraic expression for a price p decreased by 16.
Applications of Expressions
The Environmental Club is making posters. The materials for each poster cost $4. Write
an algebraic expression for the cost of p posters.
Words
Expression
$4 per poster
4
times
●
the number of posters
p
An algebraic expression for the cost of the posters is 4p.
Your turn ...
Nine students will hang t posters each. Write an algebraic expression for the total number of posters
the students will hang.
January 11, 2016
Writing Word Phrases
Write three different word phrases for x + 2.
A number plus two
A number increased by two.
Your Turn ...
Write three different word phrases for c - 50.
Evaluating Algebraic Expressions
Evaluate each expression. Use the values p = 2, n = 3, and s = 5.
a. 2p + 7
Your turn ...
(s + n) ● p
b. p + (n ● s)
Two more than a number.