About what percent is oxygen than silicon on the earths crust

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.

Find the maximum value of p= 4x + 5y subject to the following constraints :

What three-dimensional solid have 6 rectangular faces, 2 equal bases that are not rectangles and 18 edges