Evaluate 3.6x + 4.5y when x=3 and y=7

Fractions can be added and subtracted only if they're fractions. a. like b. proper c. improper d. unlike

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)

Carlos spent 1 1/4 hours doing his math homework he spent 1/4 of his time practicing his multiplication facts how many hours to carlos been practicing his multiplication facts