Surely that would mean the answer’s ambiguous, no?
No. Exponents before Subtraction. Order of operations rules.
The lack of brackets means we can’t know definitively if - is included or not
The lack of brackets mean we definitively do know that it's not included, because to be included, it would have to be in brackets.
I’d argue that -3 represents negative three, not subtract three
It's actually 0-3. There's an unwritten 0, just like if the first number was positive there's an unwritten +. 9 is actually 0+9. All operations on the number line start from 0.
negative three is it’s own distinct number from positive three
"positive 3" is actually 0+3.
The only difference is whether it's in brackets or not. To square the number -3 you need to put it in brackets, otherwise you're only squaring 3.
That's because anytime you substitute for a pronumeral, whatever the pronumeral represents goes in brackets. e.g. for x=3, 2x=2(3). So if x=-3, then x²=(-3)², as opposed to if x=3, we have -x²=-(3)². Whatever the pronumeral is equal to is inside brackets when you substitute.