this post was submitted on 12 Dec 2023
858 points (96.4% liked)
Memes
45730 readers
1097 users here now
Rules:
- Be civil and nice.
- Try not to excessively repost, as a rule of thumb, wait at least 2 months to do it if you have to.
founded 5 years ago
MODERATORS
you are viewing a single comment's thread
view the rest of the comments
view the rest of the comments
Ok, that's a start. In your simple example they are all equal, but they aren't all the same.
yn+y - 2 terms
y(n+1) - 1 term
y×(n +1) - 2 terms
To see the difference, now precede it with a division, like in the original question...
1÷yn+y=(1/yn)+y
1÷y(n+1)=1/(yn+y)
1÷y×(n +1)=(n +1)/y
Note that in the last one, compared to the second one, the (n+1) is now in the numerator instead of in the denominator. Welcome to why having the (2+2) in the numerator gives the wrong answer.
Good example wish we had better math format.
The granger issue is I thought multiple always happens first. But apparently it's what's left side first.
Multiplication and division are equal precedence (and done left to right) if that's what you're talking about, but the issue is that a(b+c) isn't "multiplication" at all, it's a bracketed term with a coefficient which is therefore subject to The Distributive Law, and is solved as part of solving Brackets, which is always first. Multiplication refers literally to multiplication signs, of which there are none in the original question. A Term is a product, which is the result of a multiplication, not something which is to be multiplied.
If a=2 and b=3, then...
axb=2x3 - 2 terms
ab=6 - 1 term
That is what I am talking about. I would have got 1 by doing 2(2+2) = 8 first. Not because of bracket but because of "implied multiplication."
What I am learning here: 8÷2(2+2) is not same as 8÷2×(2+2)
For several reasons:
Yeah, right answer but wrong reason. There's no such thing as implicit multiplication.
Correct, and that's because of Terms - 8÷2(2+2) is 2 terms, with the (2+2) in the denominator, but 8÷2×(2+2) is 3 terms, with the (2+2) in the numerator... hence why people get the wrong answer when they add an extra multiply in.
Right, because it's not "multiplication" at all (only applies literally to multiplication signs), it's a coefficient of a bracketed term, which means we have to apply The Distributive Law as part of solving Brackets.
Yeah, the actual rule is Left associativity, and going left to right is the easy way to obey that.
Lol only tool 30 years to get thos far on basics.
Just proves, never too late to learn :-)
Thanks for the effort!
You're welcome.