Posted by ann on Friday, April 13, 2012 at 11:40pm.
could you please show me how to do this problem?
ballfield costs 14,850,00 to build. the cost per city resident to build it will be based on last census. New census shows population increased by 2200 people, which reduced the cost per resident $75. what is the current population of the city?? thank you
- algebra - Reiny, Friday, April 13, 2012 at 11:57pm
The way you grouped the cost by thousands, I think you left out a zero
is it 14 850 000 ?
let currect population be x
last year's population is x - 2200
currect cost per person = 14850000/x
last year's cost per person = 14850000/(x-2200)
14850000/(x-2200) - 14850000/x = 75
14850000x - 14850000(x-2) = 75x(x-2200)
75x^2 - 165000x - 14850000(2200) = 0
x^2 - 2200x = 435 600 000
x^2 - 2200x + 1210000 = 435 600 000 + 1 210 000
(x - 1100)^2 = 436 810 000
x - 1100 = 20900
x = 22 000
current pop: = 22000
cost per person = 14850000/22000 = 675
last years' pop = 19800
cost per person = 14850000/19800 = 750
change = 750-675 = 75 , YEAHH!
- algebra - ann, Saturday, April 14, 2012 at 1:02am
yes you were right about the zero. Thank you so much for showing me how to do it. ann
Answer This Question
More Related Questions
- Math (algebra) - I have no idea how to solve this problem... A village wants to ...
- Algebra 1- 8th Grade - According to the 1990 Census, the population of the ...
- math - The2010 census shows that the population of New Jersey increased by 4.5...
- History - With over eight million people, New York City is the most heavily ...
- Math - According to the U. S. Census Bureau, the total 2008 U.S. population was ...
- Algebra 2 - According to the US Census Bureau, the population of the United ...
- Math Help - 8. One nanometer is about 0.00000003937 of an inch. What is this ...
- Math - A census-taker rings Mr. Manning's bell and asks how many children he has...
- Grade 8 Math PLZ PPL help its hard - A census-taker rings Mr. Manning's bell ...
- Algebra - Aki's Bicycle designs has determined that when x hundred bicyles are ...