Выбери верные ответы

Представь в виде дроби выражения:

1. \(\dfrac{5}{8cd}-\dfrac{3}{12cd}=\) [ \(\frac {3}{8cd}\) | \(\frac {3}{cd}\) | \(cd\) | \(\frac {1}{cd}\) ];
2. \(\dfrac{3a-7b}{a}+\dfrac{5a^2+7b^2}{ab}=\) [ \(\frac {3b+5a}{b}\) | \(\frac {b}{a}\) | \(ab\) | \(\frac {1}{ab}\) ];
3. \(4-\dfrac{9a+4b}{b}=\) [ \(-\frac {4}{b}\) | \(\frac ab\) | \(-\frac {9a}{b}\) | \(\frac 1a\) ];
4. \(\dfrac{x^2+y^2}{3x-y}+3x+y=\) [ \(\frac {1}{xy}\) | \(\frac {x}{y}\) | \(\frac{10x^2}{3x-y}\) | \( \frac{3}{3x-y}\) ].