Linear relationships can be expressed in a graphical format where the variable and the constant are connected via a straight line or in a mathematical format where the independent variable is multiplied by the slope coefficient, added by a constant, which determines the dependent variable.
If he plays 3 matches a week for 9 weeks, you have to multiply 3&9. 3*9=27 Daniel will have played 27 tennis matches by the end of the 9 weeks. Hope this helps:)
