If an expression is the difference of two squares, it will follow this format:
[tex](a)^{2}-(b)^{2}[/tex]
where a and b are integers or variables.
1) [tex]w^{2} - 121 = (w)^{2} -( 11)^{2}[/tex]
Since the expression follows the format, it's a DoTS.
2) Since the binomial has an addition sign, it isn't a DoTS.
3) [tex] n^{2}-50=(n)^{2}-(5\sqrt{2})^{2}[/tex]
The second term isn't an integer, so the expression isn't a DoTS.
4) [tex] a^{2}-36=(a)^{2}-(6)^{2}[/tex]
Since the expression follows the format, it's a DoTS.
Therefore, the first and fourth expressions are differences of two squares.
