Dielectric Constant

K1= -243.6 + 1.432 * T + 4.539 * M - 426.9 * A + 376.5 * A2 - 0.01415 * M * T - 0.3151 * A * T

T=20      M=75      A=0.16

K1= -243.6 + 1.432 *20 + 4.539 * 75 - 426.9 * 0.16 + 376.5 * 0.16^2 - 0.01415 * 75 * 20 - 0.3151 * 0.16 * 20

$${\mathtt{\,-\,}}{\mathtt{243.6}}{\mathtt{\,\small\textbf+\,}}{\mathtt{1.432}}{\mathtt{\,\times\,}}{\mathtt{20}}{\mathtt{\,\small\textbf+\,}}{\mathtt{4.539}}{\mathtt{\,\times\,}}{\mathtt{75}}{\mathtt{\,-\,}}{\mathtt{426.9}}{\mathtt{\,\times\,}}{\mathtt{0.16}}{\mathtt{\,\small\textbf+\,}}{\mathtt{376.5}}{\mathtt{\,\times\,}}{{\mathtt{0.16}}}^{{\mathtt{2}}}{\mathtt{\,-\,}}{\mathtt{0.014\: \!15}}{\mathtt{\,\times\,}}{\mathtt{75}}{\mathtt{\,\times\,}}{\mathtt{20}}{\mathtt{\,-\,}}{\mathtt{0.315\: \!1}}{\mathtt{\,\times\,}}{\mathtt{0.16}}{\mathtt{\,\times\,}}{\mathtt{20}} = {\mathtt{44.566\: \!08}}$$

Now i have no idea what is a sensible solution for this problem BUT you should have some idea.

So if this is not a sensible solution then REJECT it.

All very interesting. So what is the difficulty in substituting those data values into the equation? There are not any conversions needed, just a direct substitution. 

Almost too easy.