Here are the steps to find the perimeter of the figure:
1) Side 1 = 5 units
2) Side 2 = 8 units
3) Side 3 = 5 units
4) Side 4 = 8 units
5) Perimeter = Side 1 + Side 2 + Side 3 + Side 4
= 5 + 8 + 5 + 8
= 26
The expression for the perimeter is:
5 + 8 + 5 + 8
Combining like terms gives:
26
Therefore, the expression for the perimeter of the figure, combining like terms, is 26 units.