Oplossing:
$
\eqalign{
& 9^x \cdot 27 = \frac{1}
{{3^x }} \cr
& \left( {3^2 } \right)^x \cdot 3^3 = 3^{ - x} \cr
& 3^{2x} \cdot 3^3 = 3^{ - x} \cr
& 3^{2x + 3} = 3^{ - x} \cr
& 2x + 3 = - x \cr
& 3x = - 3 \cr
& x = - 1 \cr}
$
Oplossing:
$
\eqalign{
& \frac{{25^x }}
{{\sqrt 5 }} = 125^x \cdot 5 \cr
& \frac{{\left( {5^2 } \right)^x }}
{{5^{\frac{1}
{2}} }} = \left( {5^3 } \right)^x \cdot 5^1 \cr
& 5^{2x} \cdot 5^{ - \frac{1}
{2}} = 5^{3x} \cdot 5^1 \cr
& 5^{2x - \frac{1}
{2}} = 5^{3x + 1} \cr
& 2x - \frac{1}
{2} = 3x + 1 \cr
& - x = 1\frac{1}
{2} \cr
& x = - 1\frac{1}
{2} \cr}
$