Пошаговое объяснение:

1) 4 1/5 + 1,2 = 4,2 + 1,2 = 5,4

2) 3 4/7 * 2 4/7 = 25/7 * 18/7 = 450/49

3) 450/49 - 7,3 = 450/49 - 73/10 = 4500/490 - 3577/490 = 923/490

4) 5,4 : 923/490 = 54/10 * 490/923 = 2646/923 =

2 800/923

[tex](4 \frac{1}{5} + 1.2) \div (3 \frac{4}{7} \times 2 \frac{4}{7} - 7.3) =2 \frac{800}{923} \\ 1) \: 4 \frac{1}{5} + 1.2 = 4 \frac{1}{5} + 1 \frac{1}{5} = 5 \frac{2}{5} \\ 2) \: 3 \frac{4}{7} \times2 \frac{4}{7} = \frac{25 \times 18}{7 \times 7} = \frac{450}{49} = 9 \frac{9}{49} \\ 3) \: 9 \frac{9}{49} - 7 \frac{3}{10} = 9 \frac{90}{490} - 7 \frac{147}{490} = 8 \frac{580}{490} - 7 \frac{147}{490} = 1 \frac{433}{490} \\ 4) \: 5 \frac{2}{5} \div 1 \frac{433}{490} = \frac{27 \times 490}{5 \times 923} = \frac{27 \times 98}{923} = \frac{2646}{923} = 2 \frac{800}{923} [/tex]