#### Answer

a. $-0.44$, the profit is decreasing.
b. $0.51$, the profit is increasing.
c. $0.07$, the combined profit is increasing.

#### Work Step by Step

a. Given $f(x)=-0.44x+13.62$, we can identify the slope as $m=-0.44$, which means that the profit is decreasing at $0.44$ million dollars per year from 2012 to 2016.
b. Given $g(x)=0.51x+11.14$, we can identify the slope as $m=0.51$, which means that the profit is increasing at $0.51$ million dollars per year from 2012 to 2016.
c. We have $f(x)+(g(x)=0.07x+24.76$ and the slope is $m=0.07$, which means that the combined profit is increasing at $0.07$ million dollars per year from 2012 to 2016.