# Sum solving

**Algebra**Level pending

The sum of a finite series can be calculated using the following formula.

\[\displaystyle \sum_{a}^{n} d = na + \frac{dn(n-1)}{2}\]

where \(n\) is the number of terms, \(d\) is the common difference and \(a\) is the first term.

You are told that \(n = 56\), \(d = 12\) and \(\displaystyle\sum_{a}^{n} d = 296,016\)

Find \(a\)