[tex]3(2x - 1) + 4(x + 7) = 8x + 13[/tex]

[tex]6x - 3 + 4x + 28 = 8x + 13[/tex]

[tex]10x + 25 = 8x + 13[/tex]

[tex]10x - 8x = 13 - 25[/tex]

[tex]2x = - 12[/tex]

[tex]x = - 6[/tex]