## angelwings996 2 years ago You can model the populationof a certain city between the years 1995 and 2000 by the radical function P(x) = 55000 sqrt(x - 1945). Using this model, in what year was the population of that city 275,000? a. 1970 b. 1966 c. 1964 d. 1975

$275000=55000\sqrt{x-1945}$ calc x

2. angelwings996

Would I subtract 55000 from 275,000?

no divide both sides by 55000

4. Goten77

|dw:1357766515232:dw|

5. chphiranya

Do u know the 'BODMAS' concept ?

6. angelwings996

so $5 = \sqrt{x-1945}$

7. angelwings996

No, I only know PEMDAS

8. chphiranya

The 'BODMAS' concept tells u the order u should follow when simplifying. The order is from top to bottom. B= Brackets ( ) O= Of D= Divide M= Multiplication A= Addition S= Substraction

9. angelwings996

Okay, but if there is a square root sign, like this one, then how do I know what to do?

10. Goten77

square each side now

11. angelwings996

$5^{2} = (x-1945)^{2}$ right ?

12. angelwings996

so $25 = x - 1945 ?$

13. Goten77

no... squaring the ride side gets rid of the square root

14. Goten77

well yes 25=x-1945 *u had it written different 1 comment b4*

15. angelwings996

Oh sorry, then would I add 1945 to 25 and then it will give me x ?

16. angelwings996

So x = 1970 ? so the answer would be A ?

17. Goten77

yes

18. angelwings996

Okay thanks for your help! (: