This document contains several algebraic exercises, divided into different sections. Let's go through them step by step.

1. Developing and simplifying expressions:

   • C: $3x(2x - 1) + x(5x - 4)$
   • D: $\left(\frac{B}{2}x - 1\right)(2x + \frac{2}{5})$

2. Factoring expressions:

   • E: $49x^2 - 81$
   • F: $x^2 + 9 - (2x - 5)(x - 3)$
   • G: $4x^2 + 20x + 25$
   • H: $3x(x - 1)(3x + 2)(x + 1)$

3. Solving equations:

   • a) $4x - 16 = 0$
   • b) $x^2 + 6x + 9 = (5x + 1)(x + 3)$

Would you like me to work through the solutions for these exercises? I can start with one, or if you prefer, focus on a specific section that interests you!