[tex] \frac{3}{4} = \frac{3x}{4x} = \frac{3x - 1}{4x + 6} [/tex]
[tex] \frac{3x - 1}{4x + 6} = \frac{1}{5} [/tex]
[tex]5(3x - 1) = 4x + 6[/tex]
[tex]15x - 5 = 4x + 6[/tex]
[tex]11x = 11[/tex]
[tex]x = 1[/tex]
[tex] \frac{3x}{4x} = \frac{3.1}{4.1} = \frac{3}{4} [/tex]
[tex]3 \times 4 = 12[/tex]
