Linda Pastan Poem -- Algebra

     Algebra     by Linda Pastan

     I used to solve equations easily.
     If train A left Sioux Falls
     at nine o'clock, traveling
     at a fixed rate,
     I knew when it would meet train B.
     Now I wonder if the trains will crash;
     or else I picture naked limbs
     through Pullman windows, each
     a small vignette of longing.

      And I knew X, or thought I did,
     shuttled it back and forth
     like a poor goat
     across the equal sign.
     X was the unknown on a motor bike,
     those autumn days when leaves flew past
     the color of pencil shavings.
     Obedient as a genie, it gave me answers
     to what I thought were questions.

      Unsolved equations later, and winter now,
     I know X better than I did.
     His is the scarecrow's bitter mouth
     sewn shut in cross-stitch;
     the footprint of a weasel on snow.
     X is the unknown assailant.
     X marks the spot
     towards which we speed like trains,
     at a fixed rate.

"Algebra" is in Pastan's collection Carnival Evening:  New and Selected Poems 1968-1998 ( W W Norton, 1998).