1. Сократи дроби

Решение:

a) \( \frac{8x}{4x} = \frac{8}{4} = 2 \)

б) \( \frac{20y^3}{10y} = \frac{20}{10} \cdot \frac{y^3}{y} = 2y^2 \)

в) \( \frac{15a-20}{5} = \frac{5(3a-4)}{5} = 3a-4 \)

г) \( \frac{28a^2b^2}{42ab} = \frac{28}{42} \cdot \frac{a^2}{a} \cdot \frac{b^2}{b} = \frac{2}{3}ab \)

д) \( \frac{72a^2b^3}{24ab^2} = \frac{72}{24} \cdot \frac{a^2}{a} \cdot \frac{b^3}{b^2} = 3ab \)

е) \( \frac{18ab+27a}{9a} = \frac{9a(2b+3)}{9a} = 2b+3 \)

ж) \( \frac{35m^2n-49mn^2}{7mn} = \frac{7mn(5m-7n)}{7mn} = 5m-7n \)

и) \( \frac{54x^3y-18x^2y^2+36x^2y}{18x^2y} = \frac{18x^2y(3x-y+2)}{18x^2y} = 3x-y+2 \)

Ответ: a) 2; б) 2y²; в) 3a-4; г) \(\frac{2}{3}ab\); д) 3ab; е) 2b+3; ж) 5m-7n; и) 3x-y+2.