To find the nth term in a pattern we can use the formula:
[tex]a_n=dn+(a-d)[/tex]where d is the difference between terms and a is the firt term of the pattern.
In this case a=5 and d=5. Then the nth term is:
[tex]\begin{gathered} a_n=5n+(5-5) \\ =5n \end{gathered}[/tex]Therefore the 100 number in the pattern is:
[tex]a_{100}=5(100)=500[/tex]