In algebra, we represent an unknown number using variables. We use letters to denote these variables.
A variable is a symbol that can be used to represent one or more numbers. A variable is any symbol that may be replaced by numbers. It is a letter used to represent an arbitrary element of a set called as a variable.
For example, consider the equation 2x + 3y = 10. Here, x and y are known as variables.
Solve 2x + x
2x + x
Here, we observe that the variables are similar i.e. 2x, x. So, we need to add the variables.
2x + x = 3x