A variable is denoted by 'x,y,z…' and it can hold many values whereas a constant has a fixed value. The combination of variables and constants makes up an algebraic expression. You have already lean how to form algebraic expressions in class 6th, let's check how much you remember.
When terms have the same algebraic factors, they are like terms. When terms have different algebraic factors, they are unlike terms. Here we will learn how to write expressions and how to add expressions. While adding and subtracting expressions, first look for like terms and add them; then handle unlike terms. Let's understand this better!
The value of an algebraic expression depends on the values of the variables forming the expression. There are a number of situations in which we need to find the value of an expression, such as when we wish to check whether a particular value of a variable satisfies a given equation or not. Let's understand in detail what we mean by this!