The function below models the number of miles, in millions, US passengers 1 point travel on a train for the period of 1970 to 2000, where x is the number of
years since 1970. Which equivalent form reveals the minimum number of
miles, in millions, US passengers traveled on a train for the period of 1970
to 2000? *
M(x) = 5x^2– 160x + 6179