Optional: The substitution method in solving equations containing rational expressions
For some equations containing rational expressions, the parts of the expression can be substituted by new variables. After substitutions all the original variables are replaced by new variables, and the algebraic expressions are much simpler and easier to be solved. For example:
For some equations containing rational expressions, the parts of the expression can be substituted by new variables. After substitutions all the original variables are replaced by new variables, and the algebraic expressions are much simpler and easier to be solved. For example: