Notes 1.1 Expressions and Variables pt. 1
A numerical expression consists of numbers and operations.
A variable is a letter used to represent one more numbers.
A variable expression consists of numbers, variables, and
operations.
To evaluate a variable expression, substitute a number for each
variable and evaluate the resulting numerical expression.
A verbal model describes a problem using words as labels and using
math symbols to relate the words.
COMMON WORDS/PHRASES THAT INDICATE
OPERATIONS
ADD
SUBTRACT
MULTIPLY
DIVIDE
1.1 Practice Problems pt. 1:
Evaluate the expression when x  6 .
1. 15  x
2. 5 x
3. x  7
Evaluate the expression when a  4, b  2, c  16.
a
5. c  a
6.
7. bc
b
Write a variable expression to represent the phrase.
9. The product of 72 and a number
10. The difference of a number and 1.
11. The quotient of a number and 3.
12. 15 more than a number.
4.
x
6
8. b  a  c