4 variables turned into 1/3

explanation

Consider one variable as an Independent and give some value and substitute in every

equation, then get new equations in only 3 equations in 3 unknows, if the three

equations have unique solution or no solution. if the equations have unique solution

then the system of given four equations in 3 unknows has infinity solutions (one for every

independent variable value) or

no solution (if the rank of the augmented matrix is not same as the rank of the matrix)

i think it will be zero as slope has a formula of difference between initial and final distance divided by itz time interval