Vocabulary Basics
A symbol that represents an unknown value.
Variable.
First step to solve: x+6=14.
subtract 6 from both sides
Property: a+b=b+a.
Commutative Property.
x+5=11
x=6
The process of isolating the variable.
isolating the variable
A number without a variable attached.
constant
First step to solve: 9x=27.
divide both sides by 9.
Property: (a+b)+c=a+(b+c).
Associative Property
x−7=−2
x=5
A value used to check if a solution works.
test value
A mathematical sentence with an equal sign.
equation
The first step when solving 7x=21.
divide both sides by 7.
Property: a(b+c)=ab+ac.
Distributive Property
4x=20
x=5
A statement true for all values (like x=x).
identity equation
A mathematical sentence with an equal sign.
equation
First step to solve: x−12=−3.
add 12 to both sides.
Multiplying both sides by the same number keeps the equation true.
Multiplication Property of Equality
x/3=−4
x=−12
A statement that is always true for all values of the variable (example: x = x).
identity equation
The value that makes an equation true.
solution
First step to solve: −x=8.
divide both sides by -1.
Adding the same number to both sides keeps the equation true.
Addition Property of Equality
−2x=18
x=-9
The operation that “undoes” another operation.
inverse operation