Write an algebraic expression for the difference of 10 and u

What is the product? (x2+3y+7) [yy+1)

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 two square pyramids are similar. find the total volume of both pyramids if the ratio of their surface areas is 9/16