Nova receives a bill for her cell phone each month. she pays a flat fee of $35$35 plus $0.05$0.05 per text message. this month, her bill without taxes was $51.50$51.50. which equation gives the number of text messages, tt, she sent this month?

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)