[tex]q_{c}[/tex] = Heat released to cold reservoir
[tex]q_{h}[/tex] = Heat released to hot reservoir
[tex]W_{max}[/tex] = maximum amount of work
[tex]t_{c}[/tex] = temperature of cold reservoir
[tex]t_{h}[/tex] = temperature of hot reservoir
we know that
[tex]\frac{q_{c}}{q_{h}}=\frac{t_{c}}{t_{h}}[/tex]
[tex]q_{h} = (\frac{t_{h}}{t_{c}})q_{c}[/tex] eq-1
maximum work is given as
[tex]W_{max}[/tex] = [tex]q_{h}[/tex] - [tex]q_{c}[/tex]
using eq-1
[tex]W_{max}[/tex] = [tex](\frac{t_{h}}{t_{c}})q_{c}[/tex] - [tex]q_{c}[/tex]