List label and equation on the same line

I’m doing my (high school) math homework using LaTeX. As you might expect, I primarily use nested lists and multiline "Solve for x"-type equations.
The align environment and its other non-ed ending brethren do not allow vertical alignment of the list label with the first line of the equation (as you would get using item (begin{aligned}[t]..., say).

MWE

documentclass{article}

usepackage{amsmath}

begin{document}

Here is a list containing two unimaginative equations:

begin{enumerate}
    item 
        begin{align*}
            x^2 - 2x - 8 &= x^2 - 4x + 2x - 8
            &= (x-4)(x+2)
        end{align*}

    item
        (begin{aligned}[t]
            x^2 - 2x - 8 &= x^2 - 4x + 2x - 8
            &= (x-4)(x+2)
        end{aligned})
end{enumerate}

end{document}

Using the aligned environment (a) gives an uncentered equation and (b) deprives me of equation numbering privileges (though I would still like to know how to centre these; using centering doesn’t work, neither does inserting two hfills on either side of (...)).

An align or IEEEeqnarray environment that allows space for the list label would be ideal. I do not like the solution of aligning the equation numbers on the left, as some list items would contain text as well.

documentclass{article}

usepackage{amsmath}

begin{document}

Here is a list containing two unimaginative equations:

begin{enumerate}
    item leavevmodevspace*{-dimexprabovedisplayskip + baselineskip}begin{align}
            x^2 - 2x - 8 &= x^2 - 4x + 2x - 8
            &= (x-4)(x+2)
        end{align}

    item makebox[linewidth]{(begin{aligned}[t]
            x^2 - 2x - 8 &= x^2 - 4x + 2x - 8
            &= (x-4)(x+2)
        end{aligned})}

end{enumerate}

end{document}