Skala Termometer

(A)   Reamur

\begin{equation*}
\begin{split}
\frac{60 - 0}{x - 0} & = \frac{100 - 0}{80 - 0} \\\\
\frac{60}{x} & = \frac{\cancelto {5} {100}}{\cancelto {4} {80}} \\\\
x & = \frac{60 \:.\: 4}{5} \\\\
x & = 48^{\text{o}} \text{ R}
\end{split}
\end{equation*}

(B)   Fahrenheit

\begin{equation*}
\begin{split}
\frac{60 - 0}{x - 32} & = \frac{100 - 0}{212 - 32} \\\\
\frac{60}{x - 32} & = \frac{\cancelto {5} {100}}{\cancelto {9} {180}} \\\\
x - 32 & = \frac{60 \:.\: 9}{5} \\\\
x & = 140^{\text{o}} \text{ K}
\end{split}
\end{equation*}

(C)   Kelvin

\begin{equation*}
\begin{split}
K & = C + 273 \\\\
K & = 60 + 273 \\\\
K & = 333^{\text{o}} \text{ F}
\end{split}
\end{equation*}