What is expression

1. 1.) What is expression
In mathematics, an expression is a finite combination of symbols that is well-formed according to rules that
depend on the context. Symbols can designate numbers (constants), variables, operations, functions, and other
mathematical symbols, as well as punctuation, symbols of grouping, and other syntactic symbols.
Definition of Expression
 An Expression is a mathematical phrase that combines numbers and/or variables using mathematical operations.
 An expression is a representation of a value; for example, variables and/or numerals that appear alone or in
combination with operators are expressions.
Examples of Expression
The following are a few mathematical expressions.
 5 + 6 – (3 + 2)/18
 a + b – c
 7 + 3
4

 log3 (x + 1) + log3 (x - 3)

Solved Example on Expression
Evaluate the expression for x = 1.
2x
2
+ (x + 1)(x - 1) + 2(x - 3)
Choices:
A. – 2
B. 2
C. 0
D. 1
Correct Answer: A
Solution:
Step 1: Substitute x = 1 in the expression 2x
2
+ (x + 1)(x - 1) + 2(x - 3) and then simplify.
Step 2: = 2 + 0 + (- 4)
Step 3: = - 2


2.) What is an algebraic expression
a symbol or a combination of symbols used in algebra, containing one or more numbers, variables,
and arithmetic operations
Examples of Algebraic Expression

Solved Example on Algebraic Expression
A cassette shop charges $5 for renting a video cassette for the first day. It charges $2 extra for every
additional day. Which of these algebraic expressions tells you the amount that Sarah would pay if she rents a
video cassette for n days?
Choices:
A. $(3 + 2n)
B. $(5n + 2)
C. $ n
D. $(5 - 2n)
Correct Answer: A

2. Solution:
Step 1: $5 for the first day and $2 extra for every additional day.
Step 2: Sarah would pay $5 + (n - 1) × $2 for renting a video cassette for n days.
Step 3: So, the algebraic expression that corresponds to the amount that Sarah would pay is $(3 + 2n).


3.) What is monomial, binomial, trinomial?
A monomial is the product of non-negative integer powers of
variables. Consequently, a monomial has NO variable in its
denominator. It has one term. (mono implies one)
13, 3x, -57, x², 4y², -2xy, or 520x²y²
(notice: no negative exponents, no fractional exponents)


A binomial is the
sum of two
monomials. It has
two unlike terms.
(bi implies two)
3x + 1, x² -
4x, 2x + y,
or y - y²


A trinomial is the
sum of three
monomials. It has
three unlike terms.
(tri implies three)
x
2
+ 2x +
1, 3x² - 4x
+ 10, 2x +
3y + 2


A polynomial is
the sum of one or

3. more terms.
(poly implies many)
x
2
+
2x, 3x
3
+ x²
+ 5x + 6,
4x - 6y + 8

4.) What is a term?
Term
A Term is either a single number or a variable, or numbers and variables
multiplied together.