Substituting in the 86 for [tex]c[/tex] (which represents the temperature in Celsius) we get:
[tex]86 = \dfrac{5}{9}(F - 32)[/tex]
[tex]86 \cdot \dfrac{9}{5} = F - 32[/tex]
[tex]\dfrac{774}{5} = F - 32[/tex]
[tex]\dfrac{774}{5} + \dfrac{160}{5} = F[/tex]
[tex]F = \dfrac{934}{5} = 186.8[/tex]
The temperature in Fahrenheit would be 186.8 degrees.