[tex]x + (x + 2.5) + 2x = 12.5[/tex]
[tex]x + x + 2.5 + 2x = 12.5[/tex]
[tex]4x + 2.5 = 12.5[/tex]
[tex]4x = 12.5 - 2.5[/tex]
[tex]4x = 10[/tex]
[tex]x = \frac{5}{2} [/tex]
