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.
Quadratic equations can be solved by a process known in American English as factoring and in other varieties of English as factorising, by completing the square, by using the quadratic formula, or by graphing. Solutions to problems equivalent to the quadratic equation were known as early as 2000 BC.