Jessica has $42.60 in her piggy bank. She spent of her money at the movies and made $24.50 babysitting her cousins. How much money does she have now? A. 52.90
B. 12.84
C. 458
D. 5x-8y+7
E. 25.30

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)