 Hi and welcome to the session. My name is Shashi and I am going to help you with the following question. Question is solve the following pair of linear equations by the substitution method. First equation is 3x-y is equal to 3 and the second equation is 9x-3y is equal to 9. Let us now start with the solution. First of all we will rewrite the equations given in the question and name them as 1 and 2. Now from equation 1 we get y is equal to 3x-3. Now we name this equation as 3. Now substituting the value of y from 3 in equation number 2 we get 9x-3 multiplied by 3x-3 is equal to 9. This implies 9x-9x plus 9 is equal to 9. 9x-9x is equal to 0 so we get 9 is equal to 9. Here we can see y is equal to 3x-3 satisfy the equation number 2. So our required solution is y is equal to 3x-3 where x can take any value. Our final answer is y is equal to 3x-3 and any value or we can say x is equal to infinitely many solutions. This is our required answer. This completes the session. Hope you understood the session. Thank you and bye-bye.