YOU SAID:
The student is studying because they have to do their exam, and then they have to do their homework.
INTO JAPANESE
学生は試験をしなければならず、それから宿題をしなければならないので勉強しています。
BACK INTO ENGLISH
Students are studying because they have to take an exam and then do their homework.
INTO JAPANESE
学生は試験を受けてから宿題をしなければならないので勉強しています。
BACK INTO ENGLISH
Students are studying because they have to do their homework after taking the exam.
INTO JAPANESE
学生は試験を受けた後に宿題をしなければならないので勉強しています。
BACK INTO ENGLISH
Students are studying because they have to do their homework after taking the exam.
You've done this before, haven't you.