alignment buttons how to do [duplicate]

You are away because of the format of the created table, <table> . You added a third column that was aligned after the text boxes. The columns, we open with the tag <td> .

I put the delete button in the same column as the Change button, just to illustrate for now, removing the tags <td> and </td> in that part of the code:

    <td><input class="btn btn-primary" type="submit" value="cadastrar"></td> 
    <td><input class="btn btn-warning" type="submit" value="Alterar" style="width: 86px; height: 34px" onclick="action='alt_Materia.php'" title="Informe (Disciplina/Carga Horaria/bibliografia) a Alterar e (Codigo) cadastrado"/><!--Retirei a tag </td> daqui-->
    <!--Retirei a tag <td> daqui--><input class="btn btn-danger" type="submit" value="Deletar" style="width: 86px; height: 34px"  onclick="action='del_Materia.php'" title="Informe (Disciplina/Codigo) e clique aqui"/></td>

I updated your html here: link