Контрольные задания
Вопрос:

59–72. Выполните сложение и вычитание дробей: 59) \(\frac{b^2}{b^2+1}+\frac{1}{b^2+1}\); 60) \(\frac{x^2+b^2}{x^2-b^2}+\frac{2xb}{x^2-b^2}\); 61) \(\frac{x-2}{5}+\frac{2x+1}{15}\); 62) \(\frac{5y+8}{12}-\frac{2y-3}{6}\); 63) \(\frac4x-\frac{y}{5x}\); 64) \(\frac{3z-8}{5z^2}+\frac{z-1}{z^2}\); 65) \(\frac{8-9t}{11t}-\frac{t+4}{22t}\); 66) \(\frac{7p+1}{3p}+\frac{2p-3}{9p}\); 67) \(\frac{2a+3b}{21ab}+\frac{a-6b}{15ab}\); 68) \(\frac{5c-3d}{18cd}+\frac{c+d}{27cd}\); 69) \(\frac2{a-5}+\frac5{2a-10}\); 70) \(\frac{a-7b}{3+a}+\frac{5a+12b}{3a+9}\); 71) \(\frac{x+7}{x^2y}-\frac{y-5}{xy^2}\); 72) \(\frac{y-1}{xy^2}-\frac{x+2}{x^2y}\).

Фото задания: 59–72. Выполните сложение и вычитание дробей: 59) \(\frac{b^2}{b^2+1}+\frac{1}{b^2+1}\); 60)…Фото задания

Ответ:

  1. \(\frac{b^2+1}{b^2+1}=1\).
  2. \(\frac{x^2+2xb+b^2}{x^2-b^2}=\frac{(x+b)^2}{(x-b)(x+b)}=\frac{x+b}{x-b}\).
  3. \(\frac{3(x-2)+(2x+1)}{15}=\frac{5x-5}{15}=\frac{x-1}{3}\).
  4. \(\frac{5y+8-2(2y-3)}{12}=\frac{y+14}{12}\).
  5. \(\frac{20-y}{5x}\).
  6. \(\frac{3z-8+5z-5}{5z^2}=\frac{8z-13}{5z^2}\).
  7. \(\frac{2(8-9t)-(t+4)}{22t}=\frac{12-19t}{22t}\).
  8. \(\frac{3(7p+1)+(2p-3)}{9p}=\frac{23p}{9p}=\frac{23}{9}\).
  9. \(\frac{5(2a+3b)+7(a-6b)}{105ab}=\frac{17a-27b}{105ab}\).
  10. \(\frac{3(5c-3d)+2(c+d)}{54cd}=\frac{17c-7d}{54cd}\).
  11. \(\frac{4+5}{2(a-5)}=\frac{9}{2(a-5)}\).
  12. \(\frac{3(a-7b)+(5a+12b)}{3(a+3)}=\frac{8a-9b}{3(a+3)}\).
  13. \(\frac{y(x+7)-x(y-5)}{x^2y^2}=\frac{5x+7y}{x^2y^2}\).
  14. \(\frac{x(y-1)-y(x+2)}{x^2y^2}=-\frac{x+2y}{x^2y^2}\).