 Hi and welcome to the session. Today we will learn about simple equations. Now we know that equation is in condition on a variable. Variable means something that can vary. Change a variable takes on different numerical values that is its value is not fixed and variables are denoted by letters of alpha max such as x, y, z, a, b etc. Now in a equation equality sign for example 4x plus 5 is equal to 25 is an equation. The equality sign shows that the value of the expression to the left of this sign that is the left hand side or LHS is equal to the value of the expression to the right of the sign. The right hand side or RHA LHS is 4x plus 5 and RHS is 25. So in this equation LHS 4x plus 5 is equal to RHS that is 25. Now the equality sign between the LHS and the greater than sign or less than sign then it is not an equation. For example 4x plus 5 greater than 25 is not an equation. Equation it is not necessary that there is a number on RHS. They can also be an expression like is equal to 6x minus an equation is a condition on a variable. The condition is that the two expressions should have equal value. Now note that at least one of the two expressions must contain the variable here the variable is x. Now there is an important property of equations. An equation remains the same the expressions on the left on the right interchanged. For example the equation 4x plus 5 is equal to 6x minus 20 is the equation 6x minus 20 is equal to 4x plus 5 to check that whether the given value of the variable is the solution to the given equation or not. Suppose we are given the equation 4p minus 3 is equal to 13 and we are given the value of p as minus 4. For this we will substitute the value of p equal to minus 4 in the LHS and RHS separately and if we will get LHS is equal to RHS then that means p equal to minus 4 is the solution of the given equation. So let's start with LHS which is equal to 4p minus 3. Now on substituting the value of p equal to minus 4 we get 4 into minus 4 minus 3 so this is equal to minus 16 minus 3 which is equal to minus 19. RHS is equal to 13 so that means LHS is not equal to RHS from the given statement. We are given the statement 1 fourth of a number x minus 4 gives we have 1 fourth of a number x that means 1 by 4 of x that means we subtract 4 from 1 by 4 of x gives it is equal to is the required equation. We can also write it as x by 4 minus 4 is equal to minus 2 is equal to 18 in the form of a statement. In this equation when we take 4p then we get 18 so thus in this session we have learnt about. I hope you must have understood all the concepts goodbye take care and have a nice day.