Taking as private candidate is ok as enrichment, but you most
probably cannot use Math and Econs for entry into uni, cos
entry into uni thru A levels require 3H2, 1H1, GP and pass in 2nd
lang, and PW.
A level Math and Econs are only foundational to the course of
accountancy. Uni econs has a lot of statistical and calculation
components.
You need to consider your time management, as poly studies is
very busy, and accountancy in poly is a cut throat, hi competition
faculty.