\[\boxed{\text{289\ (289).\ }\text{Еуроки\ -\ ДЗ\ без\ мороки}}\]
Пояснение.
Решение.
\[\textbf{а)}\ a = 59,678\ldots \approx 59,7\]
\[b = 43,123\ldots \approx 43,1\]
\[a - b = 59,7 - 43,1 = 16,6.\]
\[\textbf{б)}\ a = 59,678\ldots \approx 59,68\]
\[b = 43,123\ldots \approx 43,12\]
\[a - b = 59,68 - 43,12 = 16,56.\ \]