Ответ:\(4\frac{9}{25}+6.37=4.36+6.37=10.73\).\(12\frac{9}{40}-7.84=12.225-7.84=4.385\).\(\frac{7}{8}+3.23=0.875+3.23=4.105\).Ответ: 1) 10,73; 2) 4,385; 3) 4,105.