11/15 + (-5 1/2) i know the answer is -4 23/30 but i can't get it. i've done this so far:
11/15 + (-5 1/2)
11/15 - 5 1/2

Abus travels 36 miles in 45 minutes. enter the number of miles the bus travels in 60 minutes at this rate.

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)

The length of the line segment joining the midpoints of sides ab and bc of the parallelogram abcd is 10. find the length of diagnol ac