help query

I have this query

Select t0.campo1, t0.campo2, (select t10.campo1 / 5 * 2,5 from FILE10 t10 ON t10.campo1 = t0.campo1) 'Value 1', campo2 * (select t10.campo1 / 5 * 2,5 from FILE10 t10 ON t10.campo1 = t0.campo1) 'Value 1b'

from FILE1 t0

can I use a variable to avoid the two subqueries?

thanks