What property is shown in the equation? a(b x c) = ( a x b)c

Which of the following is the missing term, a2, of the geometric sequence in which a1=2 and a3=200

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)

If the scale factor between two circles is 2x/5y what is the ratio of their areas?