Answer:
Let's denote Jessica's initial speed as \(s\). The first part of the trip, at speed \(s\), took \(t\) hours to cover 100 miles. The second part, at speed \(s + 30\) mph, took \(t - 1\) hours to cover 200 miles.
For the first part:
\[100 = s \cdot t\]
For the second part:
\[200 = (s + 30) \cdot (t - 1)\]
You can use these equations to solve for \(s\) and \(t\). Once you have those values, her average speed would be the total distance divided by the total time.
