The exponential function y = 2(3)x grows by a factor of 9 between x = 1 and x = 3. what factor does it grow by between x = 5 and x = 7?

Given the function y=2(3)^x
the growth factor between x=1 and x=3 is given by:
[2(3)^3]/[2(3)^1]
=54/6
=9
thus the growth factor between x=5 and x=7 will be as follows:
[2(3)^7]/[2(3)^5]
simplifying the above we get:
=[3^7]/[3^5]
=3^(7-5)
=3^2
=9