Tìm x , biết: 5/ 6 + ( 5 x + 3 /2 ) : 8/ 15 = 2 1 /12 .
Giải thích
2) \(\frac{5}{6} + \left( {5x + \frac{3}{2}} \right):\frac{8}{{15}} = 2\frac{1}{{12}}\)
\(\left( {5x + \frac{3}{2}} \right):\frac{8}{{15}} = \frac{{25}}{{12}} - \frac{5}{6}\)
\(\left( {5x + \frac{3}{2}} \right):\frac{8}{{15}} = \frac{{25}}{{12}} - \frac{{10}}{{12}}\)
\(\left( {5x + \frac{3}{2}} \right):\frac{8}{{15}} = \frac{{15}}{{12}}\)
\(5x + \frac{3}{2} = \frac{5}{4} \cdot \frac{8}{{15}}\)
\(5x + \frac{3}{2} = \frac{2}{3}\)
\(5x = \frac{2}{3} - \frac{3}{2}\)
\(5x = \frac{4}{6} - \frac{9}{6}\)
\(5x = \frac{{ - 5}}{6}\)
\(x = - \frac{1}{6}\)
Vậy \(x = - \frac{1}{6}\).