Ответ:\(\frac{5}{18}+\frac{4}{18}=\frac{9}{18}=\frac{1}{2}\);\(\frac{25}{34}-\frac{8}{34}=\frac{17}{34}=\frac{1}{2}\);\(3\frac{13}{45}+6\frac{17}{45}=9\frac{30}{45}=9\frac{2}{3}\);\(12\frac{43}{56}-7\frac{22}{56}=5\frac{21}{56}=5\frac{3}{8}\).