POINTS
Solve the system of equations using substitution:

The position of a moving particle is given by the position function: f(t)=-9t-t^2-0.2t^3+0.1t^4 a. at what time does the particle reverse direction? b. when is the displacement positive? (round one decimal place and answer in interval notation) c. when is the displacement negative? (round one decimal place and answer in interval notation) d. when is the particle’s acceleration positive? (round one decimal place and answer in interval notation) e. when is the particle’s acceleration negative? (round one decimal place and answer in interval notation)

Find the maximum value of p= 4x + 5y subject to the following constraints :

The bolo cavern outside of vandalia is 421 ft below sea level. a little more than75 miles away. mt owens is 7295 feet above sea level. what is the difference in elevation between the bolo cavern and mt owens?