 Hi and welcome to the session. My name is Shashi and I am going to help you with the following question. Question is form a pair of linear equations for the following problems and find their solution by substitution method. Sixth part is five years hence the age of Jacob will be three times that of his son. Five years ago Jacob's age was seven times that of his son. What are their present ages? Sun's age and the Jacob's age for solution let us assume thus is equal to y years and the Jacob's present age is equal to x condition given in the question is five years age of Jacob will be three times that of his son. Jacob's age will be three times the son's age. So we get x plus five three multiplied by y plus three y plus fifteen we get x minus three y is equal to let us name this equation as now the second condition given to us in the question is five years ago Jacob's age was to the question five years ago Jacob's age was seven times the son's age. So we get the equation is equal to seven multiplied by y minus five seven y minus thirty which further implies x minus seven y is equal to minus thirty five plus five let us name this equation as from equation one we get x is equal to ten plus three substituting this value of x in equation two we get is equal to zero this implies minus four we can say y is equal to now we will substitute this value of y in equation three to get the value of x now substituting the value of y in equation three we get x is equal to y years is equal to ten years and the Jacob's present age is equal to forty solution of equations is x is equal to forty y is equal to ten where x and y are the present ages in years of son and Jacob this completes the session hope you understood the session take care and goodbye.