الف) $\frac{x^2+8x+16}{12} \times \frac{3x+3}{x^2+5x+4} = $

ب) $\frac{a^2-1}{a+1} \times \frac{1-a^2}{a-1} = $

پ) $\frac{x^2-4}{x^2+4x+4} \times \frac{x^2-2x-8}{x^2-3x-4} = $