а) −2x + 16 = 5x + 30; б) 3 1/4 x − 4 5/7 = 3 5/12 x − 3 3/14; в) 5/12 − 7/9 x = 10 5/12 − 3x

а) \[-2x+16=5x+30\] \[-2x-5x=30-16\] \[-7x=14\] \[x=-2\]

Проверка: \(-2\cdot(-2)+16=20\), \(5\cdot(-2)+30=20\).

б) \[\frac{13}{4}x-\frac{33}{7}=\frac{41}{12}x-\frac{45}{14}\] \[\left(\frac{13}{4}-\frac{41}{12}\right)x=\frac{33}{7}-\frac{45}{14}\] \[-\frac{1}{6}x=\frac{21}{14}=\frac{3}{2}\] \[x=-9\]

в) \[\frac{5}{12}-\frac{7}{9}x=\frac{125}{12}-3x\] \[3x-\frac{7}{9}x=\frac{125}{12}-\frac{5}{12}\] \[\frac{20}{9}x=10\] \[x=\frac{9}{2}\]

Ответ: а) \(x=-2\); б) \(x=-9\); в) \(x=\frac{9}{2}\).