\[(3x + 5)(4x - 1) =\]
\[= (6x - 3)(2x + 7)\]
\[12x^{2} - 3x + 20x - 5 =\]
\[= 12x^{2} + 42x - 6x - 21\]
\[12x^{2} + 17x - 12x^{2} - 42x + 6x =\]
\[= - 21 + 5\]
\[- 19x = - 16\]
\[x = \frac{- 16}{- 19}\]
\[x = \frac{16}{19}.\]