Please help! I don’t understand this question.

The square pyramid has a volume of 441 cubic inches. what is the value of x? 1/7x is the height x is the base

Evaluate the expression. (9 + 5)(3 + 2)0

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)