In which problem situation would subtraction be used to solve the problem?

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.

Which graph represents the linear function below? y-3=1/2(x+2)

Write the equation in general quadratic form: plz !