In math mode, &
creates alternatively left-aligned and right-aligned columns. Is it possible to make a column centered?
Hello and welcome @jeanas, don’t hesitate to read How to post in the Questions category and change your topic’s title appropriately, and optionally add some tags.
As for center-aligning equations, you can do that using a grid instead, as pure equations only alternate alignment left and right.
eg
#grid(
align: (center, center),
row-gutter: 1em,
column-gutter: .5em,
columns: 2,
$a + b$, $=1$,
$d$, $=2$
)