This is the 5583rd most frequent Arabic word.
فستكون
"فستكون" means "so it will be" or "then it will be."
The word "فستكون" here serves as a future tense verb indicating a state of becoming "smarter" in the discipline of mathematics in relation to the condition provided.
إذا درستَ بجد، فستكون أذكى في الرياضيات.
If you study hard, you will become smarter in mathematics.
In this sentence, "فستكون" indicates the result of readiness derived from the preceding action of preparation, linked with logical progression.
لقد أعدتَ كل شيء مسبقًا، فستكون مستعدًا للمقابلة.
You have prepared everything in advance, so you will be ready for the interview.
The use of "فستكون" establishes a future state of enjoyment attributed to the arrangement and suitability of conditions.