Задание 6А. Выполните действия: 1) \(\frac17+\frac37\); 2) \(\frac{11}{15}-\frac7{15}\); 3) \(\frac37+\frac a7\); 4) \(\frac29+\frac x9\); 5) \(\frac1{10}+\frac{2x}{10}\); 6) \(\frac x5-\frac25\); 7) \(\frac a3+\frac b3\); 8) \(\frac{2a}{11}-\frac b{11}\); 9) \(\frac{y^2}{8}-\frac18\); 10) \(\frac6x+\frac2x\); 11) \(\frac{3a}{x}-\frac4x\); 12) \(\frac{2x^2}{y^3}+\frac{x}{y^3}\); 13) \(\frac{5b}{a^2}-\frac{3b}{a^2}\); 14) \(\frac{x}{2y}-\frac a{2y}\); 15) \(-\frac{2a}{b^2}+\frac a{b^2}\).

При одинаковых знаменателях складываем или вычитаем числители, а знаменатель оставляем прежним.

1. \(\frac17+\frac37=\frac{1+3}{7}=\frac47\).
2. \(\frac{11}{15}-\frac7{15}=\frac{11-7}{15}=\frac4{15}\).
3. \(\frac37+\frac a7=\frac{3+a}{7}\).
4. \(\frac29+\frac x9=\frac{2+x}{9}\).
5. \(\frac1{10}+\frac{2x}{10}=\frac{1+2x}{10}\).
6. \(\frac x5-\frac25=\frac{x-2}{5}\).
7. \(\frac a3+\frac b3=\frac{a+b}{3}\).
8. \(\frac{2a}{11}-\frac b{11}=\frac{2a-b}{11}\).
9. \(\frac{y^2}{8}-\frac18=\frac{y^2-1}{8}\).
10. \(\frac6x+\frac2x=\frac8x\), \(x\ne0\).
11. \(\frac{3a}{x}-\frac4x=\frac{3a-4}{x}\), \(x\ne0\).
12. \(\frac{2x^2}{y^3}+\frac{x}{y^3}=\frac{2x^2+x}{y^3}\), \(y\ne0\).
13. \(\frac{5b}{a^2}-\frac{3b}{a^2}=\frac{2b}{a^2}\), \(a\ne0\).
14. \(\frac{x}{2y}-\frac a{2y}=\frac{x-a}{2y}\), \(y\ne0\).
15. \(-\frac{2a}{b^2}+\frac a{b^2}=\frac{-2a+a}{b^2}=-\frac a{b^2}\), \(b\ne0\).