Hydrogen is the only element where the isotopes are given specific names. Common hydrogen, which has zero neutrons, is called protium. Hydrogen with one neutron is called deuterium and hydrogen with two neutrons is called tritium. See the picture at the top of the page.
The following steps can be used as a guide as you read through the examples for using the substitution method. Steps for Using the Substitution Method in order to Solve Systems of Equations. 1  Solve 1 equation for 1 variable. ( 2 Put in y = or x = form). 3  Substitute this expression into the other equation and solve for the missing variable. 4  Substitute your answer into the first equation and solve.
Know if an ordered pair is a solution to a system of linear equations in two variables or not. Solve a system of linear equations in two variables by graphing. Solve a system of linear equations in two variables by the substitution method. Solve a system of linear equations in two variables by the elimination method. In this tutorial we will be specifically looking at systems that have two equations and two unknowns. Tutorial 20: Solving Systems of Linear Equations in Three Variables will cover systems that have three equations and three unknowns.