Question

dau coroana ,va rog ca is proasta și nu stiu din pacate​

Answer 1

$\bf 1.\\ \\ \it a)\ \ 4\cdot\dfrac{7}{5}=\dfrac{4}{1}\cdot\dfrac{7}{5}=\dfrac{28}{5}=5\dfrac{3}{5}\\ \\ \\ b)\ \ 7\cdot\dfrac{3}{2}=\dfrac{7}{1}\cdot\dfrac{3}{2}=\dfrac{21}{2}=10\dfrac{1}{2}\\ \\ \\ c)\ \ 9\cdot\dfrac{10}{6}=\dfrac{9}{1}\cdot\dfrac{10}{6}=\dfrac{90}{6}=15\\ \\ \\ d)\ \ 2\cdot\dfrac{4}{11}=\dfrac{2}{1}\cdot\dfrac{4}{11}=\dfrac{8}{11}$

2.

$\it a)\ \ \dfrac{8}{3}\cdot\dfrac{5}{7}=\dfrac{40}{21}=1\dfrac{19}{21}\\ \\ \\ b)\ \ \dfrac{2}{7}\cdot\dfrac{3}{9}=\dfrac{\ 6^{(3}}{63}=\dfrac{2}{21}\\ \\ \\c)\ \dfrac{2}{6}\cdot\dfrac{3}{4}=\dfrac{\ \ 6^{(6}}{6\cdot4}=\dfrac{1}{4}$

3.

$\it a)\ \ 2\dfrac{2}{9}\cdot\dfrac{6}{25}=\dfrac{20}{9}\cdot\dfrac{6}{25}=\dfrac{\ \ 120^{(15}}{225}=\dfrac{8}{15}\\ \\ \\ \dfrac{2}{27}\cdot\dfrac{9}{8}=\dfrac{\ \ 18^{(18}}{216}=\dfrac{1}{12}$

Exercițiul  devine :

$\it \dfrac{^{4)}8}{\ 15}-\dfrac{^{5)}1}{\ 12}=\dfrac{32-5}{60}=\dfrac{\ \ 27^{(3}}{60}=\dfrac{9}{20}$