а) $$|-7.2|-|-3.4|$$
$$|-7.2| = 7.2$$
$$|-3.4| = 3.4$$
$$7.2 - 3.4 = 3.8$$
Ответ: 3.8
б) $$|-12|:|-8|$$
$$|-12| = 12$$
$$|-8| = 8$$
$$12 : 8 = \frac{12}{8} = \frac{3}{2} = 1.5$$
Ответ: 1,5
в) $$|\frac{5}{12}|+|\frac{3}{16}|$$
$$|\frac{5}{12}| = \frac{5}{12}$$
$$|\frac{3}{16}| = \frac{3}{16}$$
Приведем дроби к общему знаменателю 48:
$$\frac{5}{12} + \frac{3}{16} = \frac{5 \cdot 4}{12 \cdot 4} + \frac{3 \cdot 3}{16 \cdot 3} = \frac{20}{48} + \frac{9}{48} = \frac{20+9}{48} = \frac{29}{48}$$
Ответ: $$\frac{29}{48}$$
г) $$|-56|:|-0,7|$$
$$|-56| = 56$$
$$|-0,7| = 0.7$$
$$56 : 0.7 = \frac{56}{0.7} = \frac{560}{7} = 80$$
Ответ: 80