 Hello and welcome to the session. In this session we will learn about equation. First let's understand what an equation is. An equation is basically a condition on a variable. It is expressed by saying that an expression with a variable is equal to a fixed number. Like if we have an expression of this kind which is equal to a fixed number. So this is basically an equation. Also as you can see that equation has two sides. Left hand side that is LHS which is this side and the right hand side that is the RHS which is this side. And as you can see we have an equal to sign in between the LHS and the RHS. The equation also says that the value of the left hand side LHS is equal to the value of the right hand side that is RHS. Also we have one more point which says that the word equation is used only for equations with one or more variables. Now we discuss about the solution of an equation. The value of the variable in an equation which satisfies the equation is called a solution to the equation. Like let's consider the equation that we consider in the above section. In this the variable is this. So the solution of this equation would be equal to the value of the variable which is in this equation. Now the left hand side that is the LHS of an equation is equal to the right hand side that is RHS of an equation only for a definite value of the variable in the equation. Definite value of the variable which satisfies the equation is called the solution of the equation. Now let's see how do we find the solution of an equation. The method that we try is called the trial and error method to find the solution of an equation. In this method we give some value variable and check whether the equation. In this way we go on giving different values to the variable until we find the right value which satisfies the equation. Let's consider the above equation again. We give different values to the variable of this equation and we find that this value satisfies this equation. That is when we substitute this value of the variable in this equation we find that LHS that is the left hand side of the equation would be equal to the right hand side of the equation that is the RHS. So this value of the variable is the solution of the equation. This trial and error method is basically not a direct and practical way of finding the solution of the equation. So this completes the session. Hope you have understood what is an equation, what is the solution of the equation and the trial and error method of finding the solution of an equation.