1. Сократите дробь: a) $$rac{22p^4q^2}{99p^5q}$$; б) $$rac{7a}{a^2+5a}$$; в) $$rac{x^2-y^2}{4x+4y}$$.

a) $$rac{22p^4q^2}{99p^5q} = \frac{2 \cdot 11 \cdot p^4 \cdot q}{9 \cdot 11 \cdot p^4 \cdot p \cdot q} = \frac{2}{9p}$$ б) $$rac{7a}{a^2+5a} = \frac{7a}{a(a+5)} = \frac{7}{a+5}$$ в) $$rac{x^2-y^2}{4x+4y} = \frac{(x-y)(x+y)}{4(x+y)} = \frac{x-y}{4}$$