How to avoid extra equation numbers while using subequations?

Question

I searched through the web but I could not find the solution to my question:

I try to write equation in the following format:

TYPE a:
A = {mathematics relation-a}      3.1

TYPE b: 
B = {mathematics relation-b}      3.2

TYPE c: 
C = {mathematics relation-c}      3.3

I tried subequations but the result is like this:

\begin{subequations}
\begin{align}
    TYPE_A= \\ A = \{ relqtion equation a \} \label{eq:subeq1}\\
    TYPE_B= \\ B = \{ relqtion equation b \} \label{eq:subeq2}\\
    TYPE_C= \\ C = \{ relqtion equation c \} \label{eq:subeq3}
\end{align}
\end{subequations}

The result is:

                     TYPE a:      3.1
A = {mathematics relation-a}      3.2
                     TYPE b:      3.3 
B = {mathematics relation-b}      3.4
                     TYPE c:      3.5 
C = {mathematics relation-c}      3.6

any help would be appreciated.

Answer 1

You're not providing any "alignment hooks" in your code; hence, everythings gets pushed against the right-hand edge. The following may be more to your liking -- note the use of the symbol & on all six lines, as well as the three instances of \notag:

\documentclass{article}
\usepackage{amsmath}
\begin{document}

\begin{subequations}
\begin{align}
    &\text{TYPE A}  \notag \\ 
    &A = \{ \text{relation equation a} \} \label{eq:subeq1}\\
    &\text{TYPE B} \notag\\ 
    &B = \{ \text{relation equation b} \} \label{eq:subeq2}\\
    &\text{TYPE C} \notag\\ 
    &C = \{ \text{relation equation c} \} \label{eq:subeq3}
\end{align}
\end{subequations}

\end{document} 

Answer 2

Use \notag for the lines with the labels and alignat

\documentclass{article}
\usepackage{amsmath}

\begin{document}

\begin{subequations}
\begin{alignat}{2}
&\makebox[0pt][l]{Type A:}\notag \\
&& A &= 1+1 \label{eq:subeq1}\\
\makebox[0pt][l]{Type B:}\notag \\
&& B &= 2+2 \label{eq:subeq2}\\
&\makebox[0pt][l]{Type C:}\notag \\
&& C &= 3+3 \label{eq:subeq3}
\end{alignat}
\end{subequations}

\end{document}