(I WILL GIVE BRAINLESS) 4 Consider the two points given on the graph. Explain what they mean in terms of the situation. Cost ($) Number of Pencils

Part a : solve -vp + 40 < 65 for v part b : solve 7w - 3r = 15 for r show your work .

Can someone me and do the problem plz so i can understand it more better

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)