What I’m trying to do
Hey so I’ve been trying a few different ways to align 3 formulas to the equals sign as well as align everything to the left of the page. Most importantly I want each of these formulas to be numbered so I’ve been using the \tag{} function. I can’t seem to do all of those at the same time so I thought of using inline math $…$ which almost works but for some reason the \tag{} function doesn’t work in this case.
Things I have tried
Here is my code as it is:
$$
\begin{flalign}
\begin{array}{l}
R_{a_{Dry}}&=39.81-0.3354V_c-19.5f_d-12.05\text{d.o.c.}+0.000746V_c\times V_c\\
&-109.7f_d\times f_d+5.968\text{d.o.c.}\times\text{d.o.c.}+0.3370V_c\times\text{d.o.c.}
\end{array}\tag{1}\\
\\
\begin{array}{l}
R_{a_{Wet}}&=-16.6+0.068V_c+60.2f_2+16.29\text{d.o.c.}+0.00001V_c\times V_c\\
&+8.6f_d\times f_d-7.65\text{d.o.c.}\times\text{d.o.c.}-0.382V_c\times f_d
\end{array}\tag{2} \\
\\
\begin{array}{l}
R_{a_{Cryogenic}}&=6.44-0.0818V_c+61.3f_d+1.675\text{d.o.c.}+0.000268V_c\times V_c\\
&+43.44f_d\times f_d-0.815\text{d.o.c.}\times\text{d.o.c.}-0.0695\text{d.o.c.}\times f_d
\end{array}\tag{3}\\
\end{flalign}
$$
^Eq1
I used \begin{array} to align the \tag{} in the middle of each formula as they each take two lines but when i use array and align the align doesn’t register anymore. (See picture below)
So I guess my question is can I use \tag{} in inline maths? something like this?
$
\begin{array}{l}
R_{a_{Dry}}&=39.81-0.3354V_c-19.5f_d-12.05\text{d.o.c.}+0.000746V_c\times V_c\\
&-109.7f_d\times f_d+5.968\text{d.o.c.}\times\text{d.o.c.}+0.3370V_c\times\text{d.o.c.}
\end{array}\tag{1}
$
^Eq1
$
\begin{array}{l}
R_{a_{Wet}}&=-16.6+0.068V_c+60.2f_2+16.29\text{d.o.c.}+0.00001V_c\times V_c\\
&+8.6f_d\times f_d-7.65\text{d.o.c.}\times\text{d.o.c.}-0.382V_c\times f_d
\end{array}\tag{2}
$
^Eq2
etc...