Would someone like to help me on my math homework?

Simply 8x squared + 5(7x squared- x) - 2x =

Atriangle has a side lengths of 18cm, 80 cm and 81cm. classify it as acute obtuse or right?

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)