Answer
$f(x)=-100(1.1)^{x}$
Work Step by Step
Increasing x by 1 (fr$\quad$om 1 to 2) , f(1) is multiplied by $\displaystyle \frac{-121}{-110}=1.1$ .
So, $ b=1.1,\qquad$and$ f(x)=A(1.1)^{x}$
Now, given that $f(1)=-110,$
$-110=A(1.1)^{1}$
$\displaystyle \frac{-110}{1.1}=A$
$A=-100$
Thus,
$f(x)=-100(1.1)^{x}.$
