Solution
Since both triangles are similar we will use the ratio to solve the problem
So that
[tex]\begin{gathered} \frac{x+x+5}{12+18}=\frac{x+5}{18} \\ \frac{2x+5}{30}=\frac{x+5}{18} \end{gathered}[/tex][tex]\begin{gathered} 18(2x+5)\text{ = 30(x+5)} \\ 36x\text{ +90 = 30x + 150} \\ 36x\text{ -30x = 150 -90} \\ 6x\text{ = 60} \\ \frac{6x}{6}=\frac{60}{6} \\ x\text{ = 10} \end{gathered}[/tex]Hence, x = 10
