Constants and variables

A number that is represented by a symbol has a value.

For example, in the equation y = 5x + 3 the value of y is 3 when x = 0

A variable is a symbol that represents a value that isn’t fixed but can vary. In the equation y = 5x + 3, x and y are variables.

A constant in an equation is a value that doesn’t change.

In y = 5x + 3, 5 and 3 are constants, they don’t change.