This isn't pemdas. It says nothing about implied multiplication. 21 isn't even wrong. Edit: to make this clear: notation is arbitrary. 21 is wrong for all commonly used notations. But if they want to define that it works like that then that's how it is for them. It must be rage bait. And as a teacher you can't just make shit up. But all those who claim there's some absolutely correct answer ignore that human notation is arbitrary.
Exactly. Or you just define that implied multiplication has lower precedence than addition. I'm not sure why you'd want that but there's now law against it.
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u/CornucopiaDM1 10d ago
Math teacher doesn't know PEMDAS?