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In short, yes, you can
Explanation:
General Maths may or may not be capped, no one has ever gotten 50/50 in it. Biology is not capped, so is Chemistry, PDHPE is also capped for sure, with 50 getting 47.8 scaled.
If we go to 2008, English Standard does not appear to be capped (max of 48 scaled to 47.9), General Maths is almost certainly capped (49.5 is given to 45.5). In 2007, Standard English appears to be uncapped as well, with a 47 in 2007 scaled to 47.2. But in 2009 47 was scaled down to 46.4. In 2009, General Maths' 49.5 was scaled down to 45.3, 45.5 in 2008
So if those are your ten units, your max is: 50 (Bio), 50 (Chem), 47.9 (best ever for Std Engish), 45.5 (best ever for Gen Math), 47.8 (PDH for 50/50).
So therefore your maximum supposed aggregate is 482.4, as long as you don't break new ground by getting higher than the 'best ever', which when I say that, means breaks records set for the 2007, 2008 and 2009 HSC. 482.4 is 99.95 material, as the lowest aggregate for the 2009 HSC to get 99.95 is 478.9.