Complex sentence: After she shows him her hand, Ballinger assumes she is trying to play a practical joke on him, but when he learns otherwise, he loans her $5,500 (at 6% interest) and makes a $5000 raise for her.
Split into simpler sentences: After she shows her hand, Ballinger assumes she is trying to play a practical joke. But when he learns otherwise, he lends her $5,500 (at 6% interest) and makes a $5,000 raise for her.