The place value 8 in 281,480,100 is the 10th. And it is the same way in the other problem. How you get your answer is by counting like this EX: 1, 10, 100, 1,000, 10,000, 100,000... And so on.
Multiply the first equation with (-1)
you should get this
-6r + 3t = -6
6r + 8t = -16
start to eliminate
11t = -22
divide by 11
t = -2
substitute
6r - 3(-2) = 6
6r + 6 = 6
6r = 6 - 6
6r = 0
r=0
Since your looking for the increase you can take the number from 2004
and 2014 and turn it into a fraction
54/135
now that you've done that times it by 100 like this
54/135 x 100=
40
and that will give you the percentile which is:
40%
Hope that helps X3
