Ответ:

  1. а) \(\frac16+\frac58=\frac4{24}+\frac{15}{24}=\frac{19}{24}\).
  2. б) \(\frac78+\frac5{14}=\frac{49}{56}+\frac{20}{56}=\frac{69}{56}=1\frac{13}{56}\).
  3. в) \(\frac7{10}+\frac3{25}=\frac{35}{50}+\frac6{50}=\frac{41}{50}\).
  4. г) \(\frac{27}{70}+\frac{16}{105}=\frac{81}{210}+\frac{32}{210}=\frac{113}{210}\).
  5. д) \(\frac{11}{18}+\frac1{81}=\frac{99}{162}+\frac2{162}=\frac{101}{162}\).
  6. е) \(\frac5{12}+\frac3{44}=\frac{55}{132}+\frac9{132}=\frac{64}{132}=\frac{16}{33}\).
  7. ж) \(\frac{15}{56}+\frac{11}{84}=\frac{45}{168}+\frac{22}{168}=\frac{67}{168}\).
  8. з) \(\frac{11}{21}+\frac3{49}=\frac{77}{147}+\frac9{147}=\frac{86}{147}\).