we are given
In A 4 year period, About 80,000 acres of coastal wetlands in United States are lost each year.
so, total area =80000 acres
total time = 4 years
now, we can use formula
total change in wetlands = ( total area)/(total time)
now, we can plug values
total change in wetlands is
................Answer
Given:
Anna’s cell phone plan charges her $30 per month plus a $150 one-time activation fee.
Evelyn’s cell phone plan charges her $20 per month, plus a $450 one-time activation fee.
To find:
The number of months after which the costs for the girls’ cell phone plans the same.
Solution:
Let x be the number of months.
Total cost = Fixed cost + Variable cost
According to the question, cost equation for Anna’s cell phone is
...(i)
Cost equation for Evelyn's cell phone is
...(ii)
Equate (i) and (ii) to find the time after which the costs for the girls’ cell phone plans the same.
Divide both sides by 10.
Therefore, the costs for the girls’ cell phone plans the same after 10 months.