Answer: 5 feet.
Step-by-step explanation:
Remember that the lenghts of the sides of a regular octagon are equal.
You can observe in the figure that the lenght of a side of the regular octagon is 1.25 inches.
Let be "s" the actual length of a side of the regular octagon.
Knowing that the scale drawing has a scale of 1 inch 4 feet, you can find the actual lenght of a side of this regular octagon with:

Therefore, the actual length of a side of the octagon is 5 feet.
Answer:−9a+10b−23
Step-by-step explanation:−9a+3b−a+7b−13+a−10
Combine −9a and −a to get −10a.
−10a+3b+7b−13+a−10
Combine 3b and 7b to get 10b.
−10a+10b−13+a−10
Combine −10a and a to get −9a.
−9a+10b−13−10
Subtract 10 from −13 to get −23.
−9a+10b−23