What is 3 (x + 4) > 21

Ineed with number 17 i don’t get it at alll

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.

When a rectangle is dilated, how do the perimeter and area of the rectangle change?