Can someone just help me !

Answer:
[tex]\sqrt{a} 900[/tex] - 2
Step-by-step explanation:
I won't be answering using words.
1. (3a+2a)(6a²+1-3)
2. (5a)(6a²-2)
3. 6a² × 5a - 2 × 5a
4. 6a × 6a × 5a - 2 × 5a
5. 180a × 5a - 2
6. 900a - 2
7. [tex]\sqrt{a} 900[/tex] - 2