Determine the term of an arithmetic sequence whose ninth and sixteenth terms are
Remember the formula for the term of an arithmetic sequence is
where is the first term and is the common difference.
We know that and . Using the
general expression for the term above, we can set up two
simultaneous equations to calculate the values of and .
Subtracting the first equation from the second,
Substituting this value into the first equation,
Therefore, the formula for the term is