Look at the two equations:
3x + 6 = 21
3x + 6 < 21
Which statement best describes the process used to solve the equations?

A. In both cases, subtract 6 from both sides, but reverse the inequality sign when doing that for the inequality.
B. In both cases, divide by –3 on both sides, but reverse the inequality sign when doing that for the inequality.
C. The process is exactly the same for solving the equation and solving the inequality.
D. The process for solving the equation is entirely different from solving the inequality.

The position of a moving particle is given by the position function: f(t)=-9t-t^2-0.2t^3+0.1t^4 0 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)