Tính rút gọn: a, 2a-2/3-2b+3a-2ab : 1/4a+4 b, 2x/25-4b^2 : 1/2,5+b c, 25b^2-1/ab-3a+3b-9 : 10b-2/a+3 d, 2x-3a/2a + 3a-3x/4ax . 2ax/a-x e, 5a+5b/3ab^2 . ab/a+b + 9b-25/15b f, y/5ax-2abx . ax/y + 2b-2/6b-15 g, 2b+2/2b-b^2 : b+1/b + 2b+2/3b-6 h, 14b+19/10b-15 + 4a+4b/3a-2ab : a+b/2a

Giải thích các bước giải:

\[\begin{array}{l}
a,\\
\frac{{2a - 2}}{{3 - 2b + 3a - 2ab}}:\frac{1}{{4a + 4}} = \frac{{2\left( {a - 1} \right)}}{{\left( {3 - 2b} \right) + a\left( {3 - 2b} \right)}}.4\left( {a + 1} \right) = \frac{{8\left( {a - 1} \right)\left( {a + 1} \right)}}{{\left( {a + 1} \right)\left( {3 - 2b} \right)}} = \frac{{8\left( {a - 1} \right)}}{{3 - 2b}}\\
b,\\
\frac{{2x}}{{25 - 4{b^2}}}:\frac{1}{{2,5 + b}} = \frac{{2x}}{{\left( {5 - 2b} \right)\left( {5 + 2b} \right)}}.\left( {2,5 + b} \right) = \frac{x}{{\left( {2,5 + b} \right)\left( {5 - 2b} \right)}}.\left( {2,5 + b} \right) = \frac{x}{{5 - 2b}}\\
c,\\
\frac{{25{b^2} - 1}}{{ab - 3a + 3b - 9}}:\frac{{10b - 2}}{{a + 3}} = \frac{{\left( {5b - 1} \right)\left( {5b + 1} \right)}}{{a\left( {b - 3} \right) + 3\left( {b - 3} \right)}}.\frac{{a + 3}}{{2\left( {5b - 1} \right)}} = \frac{{\left( {5b - 1} \right)\left( {5b + 1} \right)\left( {a + 3} \right)}}{{2\left( {a + 3} \right)\left( {b - 3} \right)\left( {5b - 1} \right)}} = \frac{{\left( {5b + 1} \right)}}{{2\left( {b - 3} \right)}}
\end{array}\]