What is the common difference between the elements of the arithmetic sequence below?
-18,-22.5,-27,-31.5,-36

The graph shows the distance y, in inches, a pendulum moves to the right (positive displacement) and to the left (negative displacement), for a given number of seconds x. how many seconds are required for the pendulum to move from its resting position and return? enter your answer in the box.

Simplify the expression and find the missing terms. the simplest form of has in the numerator and in the denominator.

9/10 divide by -3/15 as a mixed number