Сначала упростим выражения для A и B.
\(A = (11\frac{21}{22}-\frac{8}{11}):7\)
\(A = (\frac{263}{22}-\frac{16}{22}):7\)
\(A = \frac{247}{22}:7\)
\(A = \frac{247}{22} \cdot \frac{1}{7} = \frac{247}{154} = \frac{22 \cdot 11 + 5}{22 \cdot 7}= \frac{22}{14}=\frac{11}{7}\)
\(B = (1,96-1\frac{2}{5}): 2,8\)
\(B = (1,96-1,4): 2,8\)
\(B = 0,56: 2,8\)
\(B = 0,2\)
Разделим число 28 пропорционально числам A и B.
A : B = \(\frac{11}{14}:\frac{1}{5}\) = \(\frac{11}{14}:\frac{2}{10}\) = \(\frac{55}{70}:\frac{14}{70}\) = \(55:14\)
28 : (55+14) = 28:69 = \(\frac{28}{69}\) - одна часть
\(\frac{28}{69} \cdot 55 = \frac{1540}{69} = 22 \frac{2}{69}\) - первая часть
\(\frac{28}{69} \cdot 14 = \frac{392}{69} = 5 \frac{47}{69}\) - вторая часть
Ответ: \(\frac{1540}{69}\) и \(\frac{392}{69}\).