Question 430444
{{{(5^(n+1) - 5^(n-1))/(3*5^(3n)) = a*5^(bn)}}}
<==> {{{(25*5^(n-1) - 5^(n-1))/(3*5^(3n))= a*5^(bn)}}}
<==> {{{(24*5^(n-1))/(3*5^(3n))= a*5^(bn)}}}
<==> {{{8*5^(-2n-1) = a*5^(bn)}}}
==> {{{(8/5)*5^(-2n) = a*5^(bn)}}}
==> {{{a = 8/5}}} and b = -2, by direct comparison.