Find the equation of the exponential function of the form $y = ab^{x}$ that passes through each of the following pairs of points.

1. $\left(1,18\right)\ \text{and}\ \left(4,3888\right)$ 

   Hint (a):

   Construct two equations by substituting the coordinates
   for $x\ \text{and}\ y$.

   $18 = ab^{1}$
   $3888 = ab^{4}$

   More Help (a):

   Use substitution to find the value of $a$ and $b$.

   $a = \frac{18}{b}$

   $3888 = \frac{18}{b}b^4$

   Answer (a):

   $y = 3\left(6\right)^{x}$

2. $\left(-2,-8\right)\ \text{and}\ \left(3,-0.25\right)$ 

   Hint (b):

   Use the same method as part (a).