226 Вправа 226Алгебра 8 клас Бевз 2025 · § 5 · стор. 51

226. Виконай множення.

а) ${\displaystyle \frac{15n^6}{-8m^2}\cdot \frac{4m^2}{5n}=}$${\displaystyle \frac{15n^6\cdot 4m^2}{-8m^2\cdot 5n}=}$${\displaystyle -\frac{3\cdot \cancel{5}{n}^5\cancel{n}\cdot \cancel{4}\cancel{m^2}}{2\cdot \cancel{4}\cancel{m^2}\cdot \cancel{5}\cancel{n}}=}$${\displaystyle -\frac{3n^5}{2}}$;

б) ${\displaystyle \frac{3a^3}{-x^4}\cdot \frac{5x}{4a}=}$${\displaystyle \frac{3a^3\cdot 5x}{-x^4\cdot 4a}=}$${\displaystyle -\frac{3a^2\cancel{a}\cdot 5\cancel{x}}{x^3\cancel{x}\cdot 4\cancel{a}}=}$${\displaystyle -\frac{15a^2}{4x^3}}$;

в) ${\displaystyle \frac{1}{2cx}\cdot \frac{-4c^2}{3x^2}=}$${\displaystyle \frac{-4c^2}{2cx\cdot 3x^2}=}$${\displaystyle -\frac{2\cdot \cancel{2}c\cancel{c}}{\cancel{2}\cancel{c}x\cdot 3x^2}=}$${\displaystyle -\frac{2c}{3x^3}}$;

г) ${\displaystyle 2a{x}^2\cdot \frac{3a}{x^3}=}$${\displaystyle \frac{2a{x}^2\cdot 3a}{x^3}=}$${\displaystyle \frac{2a\cancel{x^2}\cdot 3a}{x\cancel{x^2}}=}$${\displaystyle \frac{6a^2}{x}}$;

ґ) ${\displaystyle \frac{-7a^{2}m}{8xn}\cdot 4x^{2}n=}$${\displaystyle \frac{-7a^{2}m\cdot 4x^{2}n}{8xn}}$=

=${\displaystyle -\frac{7a^{2}m\cdot \cancel{4}x\cancel{x}\cancel{n}}{2\cdot \cancel{4}\cancel{x}\cancel{n}}=}$${\displaystyle -\frac{7a^{2}mx}{2}}$;

д) ${\displaystyle \frac{-1}{2a^{2}c}\cdot (-3a^4)=}$${\displaystyle \frac{-1\cdot (-3a^4)}{2a^{2}c}=}$${\displaystyle \frac{3a^2\cancel{a^2}}{2\cancel{a^2}c}=}$${\displaystyle \frac{3a^2}{2c}}$.