If we were to put this information into a slope-intercept form equation, the equation would be: y = 5x (dollars raised = 5 dollars per lap walked). In this case, we are going to use the variables l and d instead of x and y, respectively. The equation instead of being y = 5x, it is going to be d = 5l. In the slope-intercept form X will always be the independent variable and y the dependent variable, because the number we get for Y totally depends on what you plugged in for X. In this equation, l is the independent variable (the number of laps she walks) and d is the dependent variable (number of dollars).