html inside latex

I am new to Latex, want to know how to add html to latex.
e-g here the is sample code

begin{equation}
        begin{aligned}
        3r&= <div id="someid123">This is some div</div> quad text{(problem statement)} \
        r&=? quadtext{(divide both side)} \
        6r + 3 &= 6 * ? + 3 = ? quadtext{(substitute in $r$)}
        end{aligned}
     end{equation}

What I want is to call the div using JavaScript and replace content after latex code is generated, any idea how to do that? because right now when I add html code to latex it just messes everything up.

This is how the output looks if I add html

begin{equation} begin{aligned} 3r&=
This is some div
quad text{(problem statement)}  r&=? quadtext{(divide both side)}  6r + 3 &= 6 * ? + 3 = ? quadtext{(substitute in )} end{aligned} end{equation}