Step-by-step explanation:
[tex] \frac{x}{12} = \frac{x + 4}{5 + 12} \\ [/tex]
[tex] \frac{x}{12} = \frac{x + 4}{17} \\ [/tex]
Now cross multiply...
[tex]12(x + 4) = 17x[/tex]
[tex]12x + 48 = 17x[/tex]
[tex]12x - 17x = - 48[/tex]
[tex] - 5x = - 48[/tex]
Now divide both term by same number
[tex] \frac{ - 5x}{ - 5} = \frac{ - 48}{ - 5} \\ [/tex]
[tex]x = 9.6[/tex]
