هَؤُلَاءِ الطُّلَّابُ مُجْتَهِدُونَ.
Translation: These students are diligent.
هَؤُلَاءِ: indeclinable demonstrative in nominative position. الطُّلَّابُ: nominative apposition. مُجْتَهِدُونَ: nominative sound-masculine-plural predicate (wāw).
هَؤُلَاءِ الطَّالِبَاتُ مُجْتَهِدَاتٌ.
Translation: These female students are diligent. The demonstrative is unchanged; the predicate is feminine plural.