Ответ:
а) \(\frac7{10}+\frac1{10}=\frac8{10}=\frac45\).
б) \(\frac7{12}+\frac14=\frac7{12}+\frac3{12}=\frac{10}{12}=\frac56\).
в) \(\frac15+\frac2{15}=\frac3{15}+\frac2{15}=\frac5{15}=\frac13\).
г) \(\frac56+\frac19=\frac{15}{18}+\frac2{18}=\frac{17}{18}\).
д) \(\frac29+\frac1{12}=\frac8{36}+\frac3{36}=\frac{11}{36}\).
е) \(\frac7{24}+\frac1{60}=\frac{35}{120}+\frac2{120}=\frac{37}{120}\).
ж) \(\frac1{42}+\frac2{63}=\frac3{126}+\frac4{126}=\frac7{126}=\frac1{18}\).
з) \(\frac5{12}+\frac3{20}=\frac{25}{60}+\frac9{60}=\frac{34}{60}=\frac{17}{30}\).
