I'd like to create a matrix that has some positive power and negative power. I'd like to have an alignment to right, so for example:
\begin{array}{rr}
3 \times 10^3 & 2 \times 10^3 \\
3 \times 10^{-3} & 2 \times 10{-3}
\end{array}
In this case, the column alignment isn't good, because the negative sign at the exponent takes a little space, so the numbers aren't aligned. How can I fix this? (I think I should add a little space at the positive power too)
Then...is want to create 3 matrices in the page that should result aligned, indipendently from the values they have. For example if I write the previous matrix and then this:
\begin{array}{rr}
0 & 0 \\
0 & 1
\end{array}
they won't be aligned because the second is smaller than the first. Is there a way to set a fixed size to both matrices?


\begin{array}{rr}.