This document provides examples of representing word phrases with variable expressions and using a formula to write an expression. It gives several word problems about people's ages (Jan, Kit, Bob, Jan's sister) and represents each with a mathematical expression using variables, showing how natural language descriptions can be converted into symbolic algebraic representations.

1. Lesson 1.2: Words into Symbols - Expressions

2. Example 1: Represent each word phrase
by a variable expression

3. a) Jan’s age two years ago
b) Jan’s age five years from now
c) Jan’s father’s age, if he is three times as old as Jan
d) Jan’s cousin’s age, if he is half as old as Jan
e) Kit’s age if the sum of Jan’s and Kit’s ages is 28
f) The sum of Jan’s and Bob’s ages, if Bob is twice
Jan’s age
g) Jan’s sister’s age three years from now, if Jan’s
sister is currently 5 years older than Jan.

4. Example 3: Use a formula to write an expression