1. Two Vinyl Stores (adapted from a problem in the book Differential Equations, preliminary edition, of Blanchard, Delaney, Hall) Paul and Bob own two shops that sell vinyl records and are located near each other: Paul owns the The Sound of Blues, Jazz and Ragtime (SBJR, for short), and Bob owns the "Vintage Vinyl Shop" (VVS, for short). If x = x(t) (in dollars) represents the weekly profit of the SBJR at time t in weeks (with t = O the first week of the year), and y = y(t) (also, in dollars) represents the weekly profit of the VVS at time t again in weeks (with t = 0 the first week of the year), the rates of change of the profits are modeled by the linear system of differential equations dx = -x + 4y dt dy dt -3y - y (both in dollars per week). Interpret the meaning of the four terms, - x = -1x, +4y, -3x, and -y= -ly