What is 10+9? people said it's 21 is it true?

What expression is equivalent to (2x-1)(x-3)?

Bobby bought 1.12 pounds of turkey at a cost of 2.50 per pound. carla bought 1.4 pounds of turkey at a cost of 2.20 per pound. who spent more and by much?

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)