Hi, I haven't got a reply yet, but this is what I found from some of my own digging:
https://www.reddit.com/r/usyd/comments/1duovft
https://www.reddit.com/r/usyd/comments/1ess6g3
https://www.reddit.com/r/usyd/comments/99d1el
U can read the
faculty handbook which has all the info you need. To show u an example, I'm using the units from the
B/eco and B/arts double degree since the eco units are all similar if not same (excluding the honours program i think).
This is taken directly from the handbook:
'Mathematics is an essential tool in the study of economics. Students admitted to a Bachelor of Economics course are assumed to have prior knowledge of mathematics equivalent to a minimum result of Band 4 in the NSW Higher School Certificate course, Mathematics Advanced. Students who do not possess the assumed knowledge are strongly advised to enrol in ECON1003 Quantitative Methods in Economics in their first semester of study. The unit may be counted as an elective towards the requirements of the degree.'
TLDR to do eco at usyd, its offered as a double degree and maths is unavoidable. U can take ECON1003 (The basic/introductory math) but you'll then also have to take normal math units later on e.g. semester 2 onwards. Even the 'eco maths' has assumed knowledge of a HSC Maths advanced, ext 1 or ext 2 with a B4 minimum as said
here.
One of the reddit posts i've linked says that USYD eco tends to lean towards the maths side whereas UNSW eco is more theoretical, but keep in mind that this post was made 7yrs ago so it may be outdated. I recommend making a post on the reddit forums for more info cos I can only help u with USYD stuff.
IMO if ur really determined to do USYD eco, you should use the time now to look through HSC maths contents and the weekly plan on the unit outline so u can cross check with what topics are covered. You can also take the bridging courses in February (I think the in-person ones might be full but u can do the online ones instead).