2 9 a a + -- - 9 - - + 3 2 a a
2 9 -7 + a + -- 2 a
-7.0 + a^2 + 9.0/a^2
3 / 4 2\ 2*a + a*\9 + a - 9*a / ------------------------ 3 a
4 2 9 + a - 7*a ------------- 2 a
2 9 a -6 + a + -- - - 2 a a
/ 2\ / 2 \ \-3 + a + a /*\-3 + a - a/ --------------------------- 2 a