SOLUTION
We are told that the perimeter of the triangle is 84.
Perimeter means distance around a plane shape. So, all the sides of the triangle should add up to 84. That is
[tex]4x+x+1+3x+3=84[/tex]
Solving for x, we have
[tex]\begin{gathered} 4x+x+1+3x+3=84 \\ \text{collecting like terms } \\ 4x+x+3x=84-1-3 \\ 8x=80 \\ \text{dividing both sides by 8, we have } \\ \frac{8x}{8}=\frac{80}{8} \\ x=10 \end{gathered}[/tex]
So, x = 10. Then
[tex]\begin{gathered} WX=x+1 \\ WX=10+1 \\ WX=11 \end{gathered}[/tex]
Therefore, WX = 11
