Sophia and Charlotte has been trying to find tickets for this performance for two weeks.

Sophia and Charlotte have been trying to find tickets for this performance for two weeks. Объяснение: Так как София и Шарлотта – это множественное число, нужно использовать вспомогательный глагол "have" вместо "has" в Present Perfect Continuous. Правильная форма – "have been trying".