Gegeven: $\eqalign{ & \frac{1} {f} = \frac{1} {v} + \frac{1} {b}}$
- Druk $f$, $v$ en $b$ uit in de andere variabelen
Uitwerking
$
\eqalign{
& \frac{1}
{f} = \frac{1}
{v} + \frac{1}
{b} \cr
& \frac{1}
{f} = \frac{b}
{{vb}} + \frac{v}
{{vb}} \cr
& \frac{1}
{f} = \frac{{b + v}}
{{vb}} \cr
& f = \frac{{vb}}
{{b + v}} \cr}
$
$
\eqalign{
& \frac{1}
{f} = \frac{1}
{v} + \frac{1}
{b} \cr
& \frac{1}
{v} = \frac{1}
{f} - \frac{1}
{b} \cr
& \frac{1}
{v} = \frac{b}
{{bf}} - \frac{f}
{{bf}} \cr
& \frac{1}
{v} = \frac{{b - f}}
{{bf}} \cr
& v = \frac{{bf}}
{{b - f}} \cr}
$
$
\eqalign{
& \frac{1}
{f} = \frac{1}
{v} + \frac{1}
{b} \cr
& \frac{1}
{b} = \frac{1}
{f} - \frac{1}
{v} \cr
& \frac{1}
{b} = \frac{v}
{{fv}} - \frac{f}
{{fv}} \cr
& \frac{1}
{b} = \frac{{v - f}}
{{fv}} \cr
& b = \frac{{fv}}
{{v - f}} \cr}
$
