Verified answer

а)

[tex]5(x - 3) = 4(x + 2) \\ 5x - 15 = 4x + 8 \\ 5x - 4x = 8 + 15 \\ x = 23 [/tex]

б)

[tex] \frac{x + 3}{6} = \frac{x - 4}{7} \\ 7(x + 3) = 6(x - 4) \\ 7x + 21 = 6x - 24 \\ 7x - 6x = - 24 - 21 \\ x = - 45[/tex]