Answer:
 new signs are needed.
 new signs are needed.
Step-by-step explanation:
Given: A  -kilometer section of a highway is designated as a scenic byway. New signs will be placed at the beginning and end of this section and at every
-kilometer section of a highway is designated as a scenic byway. New signs will be placed at the beginning and end of this section and at every  Km in between.
 Km in between.
To find: How many new signs are needed?
Solution: 
We have, 
A  -kilometer section of a highway is designated as a scenic byway.
-kilometer section of a highway is designated as a scenic byway.
New signs will be placed at the beginning and end of this section and at every  Km in between.
 Km in between.
So, there are  signs placed, one at the beginning and one at the end.
 signs placed, one at the beginning and one at the end.
Now, in between these  signs  there will be
 signs  there will be   signs.
 signs.
Hence, the total new signs that are needed is  .
.