Btukfyl

I was looking for an example here about setting the lengh of the command underline.
I'm trying to produce a text on top of a line with 10cm fixed length, with text of variable size. In addition the text should be left aligned (not centered as the examples founded here produce)
Here's a minimal example. Thank you.

documentclass[a4paper,brazil, 12pt]{report}

usepackage{amsmath,amsfonts,amscd,bezier}

usepackage{amssymb}

usepackage{babel}

usepackage[latin1]{inputenc}

usepackage[shortlabels]{enumitem}

usepackage{multicol}

usepackage{tasks}

usepackage{tikz, tkz-euclide}



%%https://tex.stackexchange.com/questions/334787/constant-length-of-underline



usepackage{eqparbox, ulem}

newcommandulmakebox[2][ULB]{eqsetminwidth{#1}{10cm}underline{eqmakebox[#1]{#2}}}



newcommand{wideunderline}[2][2em]{%

    underline{makebox[ifdimwidth>#1widthelse#1fi]{#2}}%

}

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%





begin{document}



begin{minipage}{5cm}

    noindent (line 1) $mathbf{u+w=v+w},$



    noindent (line 2) $mathbf{u+w=v+w},$



    noindent (line 3)  $mathbf{u+w=v+w},$



    noindent (line 4)  $mathbf{u+w=v+w},$



    noindent (line 5)  $mathbf{u+w=v+w},$



    noindent (line 6)  $mathbf{u+w=v+w},$

end{minipage}%

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

%hspace*{4.4cm}%

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

begin{minipage}{10cm}



    underline{text here (in front of line 1) hspace{4cm}}



    underline{more text here (in front of line 2) hspace{3cm}}



    noindent ulmakebox{noindent(in front of line 3)}



    wideunderline[10cm]{noindent text here (in front of line 4)}



    begin{tikzpicture} %without text line in front of line 5

    draw (0,0) to (10,0);

    end{tikzpicture}



    begin{tikzpicture} %without text line in front of line 6

    draw (0,0) to (10,0);

    end{tikzpicture}

end{minipage}



end{document}

Not sure what's the problem. Use the [l] option for makebox.

documentclass{article}



usepackage{ulem}



newcommand{wideunderline}[2][2em]{%

  uline{makebox[ifdimwidth>#1widthelse#1fi][l]{#2}}%

}



begin{document}



(line 1) wideunderline[10cm]{text here}



(line 2) wideunderline[10cm]{text here with a p}



end{document}