This letter or symbol stands in for an unknown number.
Variable.
If x = 4, what is the value of 2x + 9?
17
Solve x − 9 = 14.
x = 23
e = d + 5 (d)
d = e -5
Expand 3(x + 4)
3x + 12
A collection of numbers, variables, and operations — but with no equals sign.
Expression
If a = 3 and b = 5, find the value of 2ab.
30
Solve 3x + 4 = 22.
x = 6
v = u + 10t (t)
t = (v-u)/t
Expand 5(2x − 3).
10x - 15
This mathematical statement shows two expressions are equal.
Equation
If v = u2 + at, find v when u = 5, a = 2, and t = 4.
33
Solve 4x − 5 = 2x + 9.
x = 7
s = h * m/4 (m)
m = (4s)/h
Expand −2x(3x + 5).
-6x2 -10x
This is a single piece of an expression, separated by + or − signs.
Term
In the formula S = ut + ½at², find S when u = 4, a = 3, and t = 2.
14
Solve
(2x + 9)/3 = x +21
x = -54
k = y3 + a
3sqrt(k-a)
Expand 3(x + 3)-2(x + 4).
x + 1
A rule or relationship written using symbols, often showing how one value depends on another.
Formula
Find E = 2x³ – 4y² + z when x = –2, y = 3, and z = 5.
-47
Solve 3(x − 4) + 2 = 2(x + 5).
x = 20
v2 = u2 + 2as (s)
s = (v^2 - u ^2)/(2a)
Expand (x − 5)(x + 6).
x2 +x -30