If y varies directly as x and z, and y=40 when x=5 and z=4 find y when x=2 and z=1

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.

Question 5 spring semester final exam math evaluate

Describe the 2 algebraic methods you can use to find the zeros of the function f(t)=-16t^2+400.