49. Приведите к наименьшему общему знаменателю дроби: а) 4/5 и 1/3; б) 4/7 и 11/14; в) 7/36 и 7/24; г) 111/375 и 103/300.

1. НОК\((5,3)=15\): \(\dfrac45=\dfrac{12}{15}\), \(\dfrac13=\dfrac5{15}\).
2. НОК\((7,14)=14\): \(\dfrac47=\dfrac8{14}\), \(\dfrac{11}{14}=\dfrac{11}{14}\).
3. НОК\((36,24)=72\): \(\dfrac7{36}=\dfrac{14}{72}\), \(\dfrac7{24}=\dfrac{21}{72}\).
4. \(375=3\cdot5^3\), \(300=2^2\cdot3\cdot5^2\), поэтому НОК\(=1500\): \(\dfrac{111}{375}=\dfrac{444}{1500}\), \(\dfrac{103}{300}=\dfrac{515}{1500}\).

Ответ: а) \(\frac{12}{15},\frac5{15}\); б) \(\frac8{14},\frac{11}{14}\); в) \(\frac{14}{72},\frac{21}{72}\); г) \(\frac{444}{1500},\frac{515}{1500}\).