Permutation, solve for n: np3 = 17(np2)

The tiles below are pieces of a normal ecg tracing representing a little less than two heartbeats at a resting rate of 80 bpm. arrange the tiles in their correct order. rank from first to last. do not overlap any tiles.

The parabola x = y² - 9 opens: a.)up b.)down c.) right d.)left

2/3(-6y+9x) expand each expression using the distributive property