Source (Bluesky)

PEMDAS says .5

It's not. You don't multiply then divide. It's more PE-MD-AS. Multiplication and division have the same priority, so are then worked from left to right.

The correct answer is 8, and only 8.

No it does not. If you treat implicit multiplication (no symbol) as exactly the same precedence as explicit, it'd be 8. Sometimes people intend it to have a higher priority, especially when it's after a division sign because they're thinking about how they'd write it on paper, as a fraction. For example, you might see 1/ab instead of 1/(ab). Strictly applying PEMDAS would say 1/ab = b/a, but if that's what you meant then you probably would have written b/a instead.

If you do the implicit multiplication first, it's 0.5.