Ответ:
а)
\(x-3\frac{13}{21}=7\frac{2}{21}-2\frac{10}{21}=4\frac{13}{21}\).
\(x=4\frac{13}{21}+3\frac{13}{21}=8\frac{26}{21}=9\frac{5}{21}\).
Ответ: \(x=9\frac{5}{21}\).
б)
\(x-3\frac{12}{17}=4\frac{10}{17}+8\frac{9}{17}=12\frac{19}{17}=13\frac{2}{17}\).
\(x=13\frac{2}{17}+3\frac{12}{17}=16\frac{14}{17}\).
Ответ: \(x=16\frac{14}{17}\).
