You can solve this analytically to get
.. 55000*(1 +x/100)^10 = 108193
.. (1 +x/100)^10 = 108193/55000
.. 1 +x/100 = (108193/55000)^(1/10)
.. x = 100*((108193/55000)^(1/10) -1) ≈ 7.00
but I find it just as fast to have a graphing calculator do it.
The city's population is increasing 7% per year.
Answer: (30m-9n)/270
First we start with m/9-n/30.
We multiply the denominators to get 270.
Then we multiply the numerators by the original denominators to get (30m-9n).
To check, we can use m=2, and n=4
2/9-4/30=4/45
(30*2-9*4)/270=24/270=4/45
Choice b would be correct since the slope of the line is negative !
Fifty-five and twelve hundreths