Answer:
25 miles
Step-by-step explanation:
Given: A boat sail 20 miles west of the port and then 15 miles south to an island.
Picture attached.
The distance from port to island could be measured in a straight line. It will form a hypotenous.
∴ we can use Pythogorean theorem to find the distance.

Where, "a" is adjacent= 20 miles and "b" is opposite= 15 miles.

⇒ 
⇒
⇒
We know
.
∴
∴ Distance of Port from the Island is 25 miles.
I redrew the triangle (just turned it around it make it easier to understand).
Answer:

Step-by-step explanation:
Hope this helps! Have a great day ahead. Happy halloween :) Stay Safe <33
I think it’s -1 because with rise/run it goes down 2 and over 2 but the line is going down, so it’s negative.