Задача 21. Найдите корень уравнения \(10\left( {x-9} \right) = 7\)
Решение
\(10\left( {x-9} \right) = 7\,\,\,\,\,\, \Leftrightarrow \,\,\,\,\,\,10x-90 = 7\,\,\,\,\,\, \Leftrightarrow \,\,\,\,\,\,10x = 90 + 7\,\,\,\,\,\, \Leftrightarrow \)
\( \Leftrightarrow \,\,\,\,\,\,10x = 97\,\,\,\,\,\, \Leftrightarrow \,\,\,\,\,\,x = \dfrac{{97}}{{10}}\,\,\,\,\,\, \Leftrightarrow \,\,\,\,\,\,x = 9,7.\)
Ответ: 9,7.