Hey there!!
How do we find slopes ?
Slope = 
We are given with two co-ordinates :
(-1,8) and (3,-4)
Hence, the slope is :

...
= -3
The slope is -3.
Hope my answer helps!
Answer: A 40 feet
Explanation:
If a building is 380 feet tall and the elevator has to descend 420 feet to get to the underground parking garage. So 420 - 380 to remove the height of the building from the equation. This would give us 40 feet underground left until the elevator reaches its desired destination.
Use the PACED decision-making process to make a decision or make a choice. The steps to follow when making a decision can be easily remembered when you use the word PACED:
P - What is the PROBLEM - Why is there a need to make a choice?
A - What are the ALTERNATIVES - What are the possible choices available?
C - Establish the CRITERIA - Why is one choice better than the other?
E - EVALUATE the alternatives - How well does each choice meet the criteria?
D - Make a DECISION - What is the best choice?