Please help on 19 and 20

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.

Rose bought a new hat when she was on vacation. the following formula describes the percent sales tax rose paid b=t-c/c

Below are two different functions, f(x) and g(x). what can be determined about their slopes? f(x)= −1x + 1 the function g(x) going through 0, 3 and 1, 1