Question 979663
You may have a choice of {{{C=pb^x}}}  or  {{{C=pe^(kx)}}}.  You can use any base b you want, which may be 10, or 2, or e, and the initial cost for a pound is the variable p.  e is the base of the Natural Logarithm, for the second choice of equation model, which will involve a constant k as part of the exponent.



Which form of the model?  Your choice.


This help posting will use the first one.
EITHER base you like, find logarithm of both sides.  I will use natural log base just for convenience.  You use base ten, if you want.



{{{ln(C)=ln(pb^x)}}}
{{{ln(C)=ln(p)+ln(b^x)}}}
{{{ln(C)=ln(p)+x*ln(b)}}}
{{{highlight_green(ln(C)=ln(b)*x+ln(p))}}}-------This is a linear equation having slope  {{{ln(b)}}} and vertical axis intercept {{{ln(p)}}}.


The points to use for this linear form need to use natural log of the costs, because the linear equation defines a formula for the natural log of cost.


The ordered pairs for your points are   (2006, ln(66)) and  (2010, ln(83)).


You already have learned what to do with a system of two linear equations.  Using each pair of points gives a corresponding equation, and the new unknowns to solve for will be  {{{ln(b)}}} for slope and  {{{ln(p)}}}  for vertical axis intercept.