196

16574 readers

1933 users here now

Be sure to follow the rule before you head out.

Rule: You must post before you leave.

^other^ ^rules^

founded 1 year ago

MODERATORS

[email protected]

421

Glitch in the matrix (ani.social)

submitted 11 months ago by [email protected] to c/[email protected]

575 comments fedilink hide all child comments

you are viewing a single comment's thread
view the rest of the comments

[–] [email protected] 11 points 11 months ago (3 children)

If you agree that parenthesis go first then the equation becomes 8/2x4. Then it's simply left to right because multiplication does not take precedence over division. What's the nuanced talk? That M comes before D in PEMDAS?

[–] [email protected] 4 points 11 months ago (1 children)

Finally someone in here who knows math. Thank you.

[–] [email protected] 2 points 11 months ago

My observation was mainly based on this other comment

https://programming.dev/comment/5414285

In this more sophisticated convention, which is often used in algebra, implicit multiplication is given higher priority than explicit multiplication or explicit division, in which those operations are written explicitly with symbols like x * / or ÷. Under this more sophisticated convention, the implicit multiplication in 2(2 + 2) is given higher priority than the explicit division in 8÷2(2 + 2). In other words, 2(2+2) should be evaluated first. Doing so yields 8÷2(2 + 2) = 8÷8 = 1. By the same rule, many commenters argued that the expression 8 ÷ 2(4) was not synonymous with 8÷2x4, because the parentheses demanded immediate resolution, thus giving 8÷8 = 1 again.

[–] [email protected] 1 points 8 months ago

If you agree that parenthesis go first then the equation becomes 8/2x4

No, it becomes 8/(2x4). You can't remove brackets unless there's only 1 term left inside. Removing them prematurely flips the 4 from being in the denominator to being in the numerator, hence the wrong answer.