I see the photo you uploaded with a list of algebraic expressions. Let's work through them! Could you specify which problem(s) you'd like help with, or should I begin with a general approach to some of these?

Here's a breakdown of the questions seen in the image (31-40):

1. $6p^2 - 9pq - 81q^2$
2. $6x^4 + bx^2 - 15b^2$
3. $5x^2 + 26xy + 5y^2$
4. $18x^2 + 19xy - 12y^2$
5. $b(ax^2 - c) + x(ax^2 - c)$
6. $ab(x^2 + 1) + (a^2 + b^2)x$
7. $x^3 + 2x^2 + x + 2$
8. $6ax + 4ay - 9bx - 6by$
9. $ax^2 - 3b - a + 3bx^2$
10. $a^2 - b^2 + a - b$

Let me know which ones you would like me to solve or explain!