№ 5.8 Алгебра = № 10.8 Математика
Виконайте дію:
1. $ \frac{a}{16m^2}\cdot12m;$
2. $\ a^3\cdot\frac{7x^3}{a^2};$
3. $ -\frac{7y}{4x^2}\cdot12xy^3;$
4. $ 5cm^4\cdot\left(-\frac{m}{15c}\right);$
5. $ -5ab^2\cdot\left(-\frac{1}{10ab}\right);$
6. $13c^2d\cdot\frac{7}{26c^3d^2}.$
Розв'язок:
1. $ \frac{a}{16m^2}\cdot12m=\frac{a\cdot12m}{16m^2}=$
$= \frac{12a}{16m}=\frac{3a}{4m};$
2. $\ a^3\cdot\frac{7x^3}{a^2}=\frac{7x^3a^3}{a^2}=7x^3a;$
3. $ -\frac{7y}{4x^2}\cdot12xy^3=-\frac{7y\cdot12xy^3}{4x^2}=$
$= -\frac{84xy^4}{4x^2}=-\frac{21y^4}{x};$
4. $ 5cm^4\cdot\left(-\frac{m}{15c}\right)=-\frac{5cm^4\cdot m}{15c}=$
$= -\frac{5cm^5}{15c}=-\frac{m^5}{3};$
5. $ -5ab^2\cdot\left(-\frac{1}{10ab}\right)=\frac{5ab^2}{10ab}=\frac{b}{2};$
6. $13c^2d\cdot\frac{7}{26c^3d^2}=\frac{13c^2d\cdot7}{26c^3d^2}=$
$= \frac{91c^2d}{26c^3d^2}=\frac{7}{2cd}.$