Just subtract 622 feet from 486 feet to get the change in elevation. The result will be negative because your friend's house is at a lower elevation than yours.
Now find the mean change in elevation per mile by dividing (486 ft - 622 ft) by 4 miles:
-136 ft
----------- = -34 ft/mile
4 mi
Answer:
D
Step-by-step explanation:

=
Factor out 2 on the numerator and 2x on the denominator.
= 
Cancel the factor (x + 2) on the numerator/ denominator
=
← cancel the 2 on numerator/ denominator
=
: x ≠ 0
The answer is infinetely many solutions.
6+6=6+6
12=12
What is the X in the problem
Answer:
2x + 3y > 100
x + y = 40
Step-by-step explanation:
This is the answer because it shows the price of each and the combined products equaling more than 100 dollars, and the bottom one shows that the combined total of jewelry can not exceed 40 pieces.