Among Spainâs indigenous animals are a wide variety of deer, Iberian wild goats, tortoises, bats, snakes, and small reptiles and amphibians.
Solving Systems of Equations by Substitution Method. Substitution is the most elementary of all the methods of solving systems of equations. Substitution method, as the method indicates, involves substituting something into the equations to make them much simpler to solve.
Common methods for the qualitative analysis of nonlinear ordinary differential equations include: 1  Examination of any conserved quantities, especially in Hamiltonian systems. 2  Examination of dissipative quantities (see Lyapunov function) analogous to conserved quantities. 3  Linearization via Taylor expansion.