For this case we have that by definition, the perimeter of a rectangle is given by:
[tex]P = 2a + 2b[/tex]
Where:
a, b: They are the sides of the rectangle.
We have according to the data that:
[tex]a = 5x-8\\b = 3x[/tex]
SUBSTITUTING:
[tex]P = 2 (5x-8) +2 (3x)\\P = 10x-16 + 6x\\P = 16x-16[/tex]
Thus, the perimeter of the rectangle is:[tex]P = 16x-16[/tex]
Answer:
[tex]P = 16x-16[/tex]