Answer:
4x+12
Step-by-step explanation:
Assuming the shape is a rectangle with
length=x+5 units and width=3x+1 units.
The perimeter is given by:
[tex]p = 2(l + w)[/tex]
We substitute the expression for the length and width to get:
[tex]p = 2(x + 5 + 3x + 1)[/tex]
We simplify within the parenthesis to get:
[tex]p = 2(4x + 6)[/tex]
We now expand to get:
[tex]p = 8x + 12[/tex]
The expression for the perimeter is 4x+12