An expression is a math phrase made using:

• numbers

• variables (letters like x or y)

• operations (+, −, ×, ÷)

• and sometimes exponents (like x^2)

Example of an expression:

3x+5

This is not an equation because there’s no equal sign.

 Main Parts of an Expression 

1️⃣ Terms

Terms are the pieces separated by + or − signs.

Example:

7x – 4 + 2y

The terms are:

• 7x

• −4

• 2y

📌 Important: The sign belongs to the term.
So −4 is one term (not just 4).

2️⃣ Coefficients

A coefficient is the number that multiplies a variable.

Example:

6x

• 6 is the coefficient

• x is the variable

More examples:

• In −9y, the coefficient is -9

• In x, the coefficient is 1 (because 1x=x)

• In −a, the coefficient is -1 (because −1a=−a)

3️⃣ Variables

A variable is a letter that stands for a number you don’t know yet.

Examples:

• $x$, $y$, $a$, $n$

Example:

4x+2

• variable = x

4️⃣ Constants

A constant is a number without a variable (just a plain number).

Example:

8x+11

• constant = 11

Another example:

−3+5y

• constant = -3

5️⃣ Operators (Operations)

Operators are the math actions:

• $+$ add

• $-$ subtract

• $\times$ multiply

• $÷$ divide

Example:

2x+9

The operator is +

6️⃣ Factors

Factors are things being multiplied together.

Example:

$$5x$$

Factors are:

• 5 and x

Example:

(3)(x)(y)

Factors are:

• 3, x, and y

7️⃣ Exponents

Exponents tell you how many times a variable is multiplied by itself.

Example:

x^3

This means:

x⋅x⋅x

In:

4x^2

• 4 is the coefficient

• x is the variable

• 2 is the exponent

8️⃣ Like Terms (Super Important)

Like terms have the same variable part.

Examples of like terms:

• 3x and −10x

• 5y^2 and 2y^2

• $7$ and $-4$ (constants are like terms)

Not like terms:

• $x$ and x^2

• $2x$ and 2y

• 3a and 3ab