The numerator and denominator of a fraction are in the ratio of 3 to 5. if the numerator and denominator are both increased by 2, the fraction is now equal to . if n = the numerator and d = the denominator, which of the following systems of equations could be used to solve the problem?
a. 5n = 3d and 3n + 6 = 2d + 4
b. 5n = 3d and 4n + 4 = 3d + 6
c. 3n = 5d and 3n + 6 = 2d + 4

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)