1. Сократить дроби

a) \( \frac{22p^4q^2}{99p^5q} = \frac{2}{9pq} \). b) \( \frac{7a}{a^2+5a} = \frac{7}{a+5} \). c) \( \frac{x^2-y^2}{4x+4y} = \frac{(x-y)(x+y)}{4(x+y)}=\frac{x-y}{4} \).