Chapter 1.1, Problem 23E

The following systems are models of the populations of pairs of species that either compete for resources (an increase in one species decreases the growth rate of the other) or cooperate (an increase in one species increases the growth rate of the other). For each system, identify the variables (independent and dependent) and the parameters (carrying capacity, measures of interaction between species. etc.) Do the species compete or cooperate? (Assume all parameters are positive.)
(a) $\begin{array}{l}\frac{dx}{dt}=\alpha x-\alpha \frac{x^2}{N}+\beta xy\\ \frac{dy}{dt}=\gamma y+\delta xy\end{array}$     (b) $\begin{array}{l}\frac{dx}{dt}=-\gamma x+\delta xy\\ \frac{dy}{dt}=\alpha y+\beta xy\end{array}$