The perimeter is the sum of all sides, therefore:
[tex]P=(2x+4)+(x)+(3x+3)[/tex]
Since the perimeter is 55 units:
[tex]55=2x+4+x+3x+3[/tex]
Add like terms:
[tex]55=6x+7[/tex]
Solve for x:
[tex]\begin{gathered} 55-7=6x \\ 48=6x \\ x=\frac{48}{6} \\ x=8 \end{gathered}[/tex]
Answer:
x = 8
