Since this sequence is arithmetic, what has to be true about the differences between terms?

How many times would you add the difference to get from $2$ to $35$?

$2+d+d+d=35$

$d=11$

Since you know the first term and the common difference, you can write all four terms of the sequence.

Use the sequence to write a system of equations: $a−b=?$ and $a+b=?$

$a=18.5,b=5.5$