Which expression has same value as 7*99

What is the sum or difference 4x10 – 9x10 (1 point) –5x10 –5x20 –36x10 –36x20 this is the cca test i need all the answers this is the first 2

Its worth 10000000 points need asap if you answer correctly ill mark brainliest

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)