# What Are the Definitions in Algebra?

• This is an equation, because it has an = sign.

• The 3, 5, 2 and 4 are constants: they only have a fixed value.

• The x, y and z are variable: they are letters that stand for numbers .

Note: The value they take can vary (hence variable). The equation is satisfied if

x = 1, y = 3 and z = 4, or
x = 1, y = 2 and z = -1, or
x = 2, y = 1 and z = 3...

• The 3 is a coefficient: it is a constant in front of a letter.

Note: The x and y also have a coefficient, eben though there is no number in front of them. If there is no number, assume the coefficient is 1.

• The + and the - are operators: operators include +, -, × and ÷.

• The 3x2, 5(y - 2), 4 and z are terms: a collection of letters, numbers, exponents and parentheses.

Note: terms are separated by + or - operators.

• The 2 in the x2 is an exponent: the x is multiplied by itself 2 times; x × x.

• The y - 2 is a bracket (or parentheses): the terms in the bracket are grouped together into one term, so 5 is multiplied by (y - 2).

• The 3x2 + 5(y - 2) and 4 + z are expressions: one term or several terms that are added (+) or subtracted (-) together.

Note: the = separates expressions.

# What Are Polynomimials?

A polynomial is an expression with two or more terms. It consists of constants, variables and exponents:

# What Are Like Terms?

Like terms are terms that have the same combination of variables and exponents.

are all like terms. They all have the same combination of letters and exponents: x2y. The only difference is the of each term.

Algebra Lessons
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##### Note
WHAT IS ALGEBRA?

Algebra is a branch of mathematics that uses letters or symbols to represent variables, values or numbers, which can then be used to express operations and relationships and to solve equations.

WHAT'S IN A NAME?

Algebra comes from the Arabic word 'al-jebr', meaning "reunion of broken parts".

# ALBERT EINSTEIN AND ALGEBRA

The famous scientist Albert Einstein learned algebra from a young age.

His Uncle Jakob gave him books on the subject and called algebra "a merry science".

He compared algebra to hunting a little animal. You didn't know the name of the animal, so you called it "x". When you finally caught the animal you gave it the correct name.