Đáp án:

$\begin{array}{l}
B5)1)\\
a)\dfrac{{2525}}{{5353}} = \dfrac{{25.101}}{{53.101}} = \dfrac{{25}}{{53}}\\
\dfrac{{252525}}{{535353}} = \dfrac{{25.10101}}{{53.10101}} = \dfrac{{25}}{{53}}\\
Vậy\,\dfrac{{25}}{{53}} = \dfrac{{2525}}{{5353}} = \dfrac{{252525}}{{535353}}\\
b)\dfrac{{3737}}{{4141}} = \dfrac{{37.101}}{{41.101}} = \dfrac{{37}}{{41}}\\
\dfrac{{373737}}{{414141}} = \dfrac{{37.10101}}{{41.10101}} = \dfrac{{37}}{{41}}\\
 \Leftrightarrow \dfrac{{37}}{{41}} = \dfrac{{3737}}{{4141}} = \dfrac{{373737}}{{414141}}\\
2)\dfrac{a}{b} = \dfrac{{11}}{{13}};b - a = 6\\
 \Leftrightarrow b = a + 6\\
 \Leftrightarrow \dfrac{a}{{a + 6}} = \dfrac{{11}}{{13}}\\
 \Leftrightarrow 13.a = 11.\left( {a + 6} \right)\\
 \Leftrightarrow 13.a = 11.a + 66\\
 \Leftrightarrow 13.a - 11.a = 66\\
 \Leftrightarrow 2a = 66\\
 \Leftrightarrow a = 33\\
 \Leftrightarrow b = 33 + 6 = 39\\
 \Leftrightarrow \dfrac{{33}}{{39}} = \dfrac{{11}}{{13}}\\
B6)\\
a) - \dfrac{{22}}{{55}} = \dfrac{{ - 22:11}}{{55:11}} = \dfrac{{ - 2}}{5}\\
\dfrac{{ - 26}}{{65}} = \dfrac{{ - 26:13}}{{65:13}} = \dfrac{{ - 2}}{5}\\
 \Leftrightarrow  - \dfrac{{22}}{{55}} = \dfrac{{ - 26}}{{65}}\left( { =  - \dfrac{2}{5}} \right)\\
b)\dfrac{{114}}{{122}} = \dfrac{{114:2}}{{122:2}} = \dfrac{{57}}{{61}}\\
\dfrac{{5757}}{{6161}} = \dfrac{{5757:101}}{{6161:101}} = \dfrac{{57}}{{61}}\\
 \Leftrightarrow \dfrac{{114}}{{122}} = \dfrac{{5757}}{{6161}}
\end{array}$