Algebra - Basic Definitions

Question 0

What is a Constant

Answer 0

A number on its own is called a Constant.

Example: in “x + 5 = 9”, 5 and 9 are constants

Question 1

What is a variable?

Answer 1

A variable is an alphabetic character representing a number. A symbol for a number we don’t know yet. It is usually a letter like x or y.

Example: X+2=3
The letter X is the variable in the equation

Question 2

What is a Coefficient

Answer 2

A Coefficient is a number used to multiply a variable

Example: 4x means 4 times x, so 4 is a coefficient

Question 3

What is a Term?

Answer 3

A Term is either a single number or a variable, or numbers and variables multiplied together.

Example: 4X-7=5
4X,7,5 are all separate terms

Question 4

What is an expression?

Answer 4

An Expression is a group of terms (the terms are separated by + or − signs)

Example: 4X-7=5
The (4X-7) is an expression

Question 5

What is a Polynomial?

Answer 5

A polynomial can have constants, variables and the exponents 0,1,2,3,…
But you never have division by a variable. Like (3XY^-2)

Example of a Polynomial: 3x2 + x - 2

Question 6

Monomial, Binomial, Trinomial

Answer 6

There are special names for polynomials with 1, 2 or 3 terms:

Monomial: 3xy^2 (1 term)
Binomial: 5X-1 (2 terms)
Trinomial: 3X+5Y^2-3 (3 terms)