1.Сократите дробь: a) 25a3 15a 6) 8x-16y 5x-10y B) y2-81 18-2y

a) $$ \frac{25a^3}{15a} = \frac{5a^2}{3} $$

б) $$ \frac{8x-16y}{5x-10y} = \frac{8(x-2y)}{5(x-2y)} = \frac{8}{5} $$

в) $$ \frac{y^2-81}{18-2y} = \frac{(y-9)(y+9)}{-2(y-9)} = -\frac{y+9}{2} $$

Ответ: а) $$\frac{5a^2}{3}$$, б) $$\frac{8}{5}$$, в) $$\frac{-(y+9)}{2}$$