a) \(\dfrac{24}{32}=\dfrac{15}{20};\dfrac{32}{24}=\dfrac{20}{15};\dfrac{15}{24}=\dfrac{20}{32};\dfrac{32}{24}=\dfrac{24}{15}\)

b) \(\dfrac{4,8}{25,6}=\dfrac{0,6}{3,2};\dfrac{25,6}{4,8}=\dfrac{3,2}{0,6};\dfrac{25,6}{3,2}=\dfrac{4,8}{0,6};\dfrac{3,2}{25,6}=\dfrac{0,6}{4,8}\)

a: \(\dfrac{24}{32}=\dfrac{15}{20};\dfrac{24}{15}=\dfrac{32}{20};\dfrac{32}{24}=\dfrac{20}{15};\dfrac{15}{24}=\dfrac{20}{32}\)

b: \(\dfrac{4.8}{25.6}=\dfrac{0.6}{3.2};\dfrac{4.8}{0.6}=\dfrac{25.6}{3.2};\dfrac{25.6}{4.8}=\dfrac{3.2}{0.6};\dfrac{0.6}{4.8}=\dfrac{3.2}{25.6}\)

Lời giải:

a. $\frac{3}{-2}=\frac{9}{-6}$

$\frac{-2}{3}=\frac{-6}{9}$

$\frac{3}{9}=\frac{-2}{-6}$

$\frac{9}{3}=\frac{-6}{-2}$

b.

$\frac{12}{16}=\frac{3}{4}$

$\frac{16}{12}=\frac{4}{3}$

$\frac{12}{3}=\frac{16}{4}$

$\frac{3}{12}=\frac{4}{16}$

Tỉ lệ thức là đẳng thức của hai tỉ số \(\frac{a}{b}=\frac{c}{d}\)

a) \(12.20=15.16\)

\(\Leftrightarrow\)\(\frac{12}{15}=\frac{16}{20}\)  ; \(\frac{20}{15}=\frac{16}{12}\);

\(\Leftrightarrow\) \(\frac{12}{16}=\frac{15}{20}\);  \(\frac{10}{16}=\frac{15}{12}\)

b) \(\left(a-b\right).\left(a+b\right)=2.3\)

\(\Leftrightarrow\)\(\frac{\left(a-b\right)}{2}=\frac{3}{\left(a+b\right)}\);  \(\frac{\left(a-b\right)}{3}=\frac{2}{\left(a+b\right)}\)

\(\Leftrightarrow\)\(\frac{\left(a+b\right)}{3}=\frac{2}{\left(a+b\right)}\); \(\frac{\left(a+b\right)}{2}=\frac{3}{\left(a-b\right)}\)

0,36.4,25 = 0,9.1,7

\(\frac{12}{15}=\frac{16}{20};\frac{12}{16}=\frac{15}{20};\frac{20}{16}=\frac{15}{12};\frac{20}{16}=\frac{15}{12}\)

\(1.\)

\(a,\)

\(7.\left(-28\right)=\left(-49\right).4\)

Ta có :   \(\frac{7}{-49}=\frac{4}{-28}\)                                                     \(\frac{-28}{4}=\frac{-49}{7}\)

                 \(\frac{7}{4}=\frac{-49}{-28}\)                                                      \(\frac{-28}{-49}=\frac{4}{7}\)

\(b,\)

\(0,36.4,25=0,9.1,7\)

Ta có :   \(\frac{0,36}{0,9}=\frac{1,7}{4,25}\)                                                        \(\frac{0,36}{1,7}=\frac{0,9}{4,25}\)

              \(\frac{4,25}{0,9}=\frac{1,7}{0,36}\)                                                        \(\frac{4,25}{1,7}=\frac{0,9}{0,36}\)