\(\frac{2x}{5y} = 6\)
\(2x = 6 * 5y\)
\(2x = 30y\)
\(\frac{2x}{30} = y\)
\(y = \frac{x}{15}\)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
\(\frac{11}{4} - a = 3\)
\(-a = 3 - \frac{11}{4}\)
\(a = \frac{11}{4} - 3\)
\(a = \frac{11}{4} - \frac{12}{4}\)
\(a = - \frac{1}{4}\)
