# Is the answer 17 or 21??

Is the answer 17 or 21??

1. 1 month ago
Anonymous

Also, this isn't even ambiguous.

2. 1 month ago
Anonymous

2+5(8-5)
2+5(3)
2+15
17

Parentheses
Exponents
Multiplication
Division
Subtraction

Use PEMDAS Anon!

• 1 month ago
Anonymous

>5(3)
Which fucking retard uses this convention? This is used for uncertainties, 1.23(45) means [math]1.23 pm 0.45[/math], so 5(3) would mean [math]5 pm 3[/math]. Use a multiplication sign of your choice if you want to express multiplication.

• 1 month ago
Anonymous

In certain contexts it does. In arithmetic it means multiply by whatever is in the parentheses.

>Use a multiplication sign of your choice if you want to express multiplication.
No. I'm not typing x*y*z*n*a*b*c. I'm writing xyznabc because everyone knows what it means and it saves space on the page.

• 1 month ago
Anonymous

For symbols sure, you can omit the sign. [math]F=m,a[/math]. But not for numbers.

• 1 month ago
Anonymous

• 4 weeks ago
Anonymous

>too retarded to grasp the concept of contexts

• 4 weeks ago
Anonymous

Pemdos is shit because most people subconsciously place implied multiplication over regular multiplication and division.

That being 17 is the only correct answer

• 4 weeks ago
Anonymous

*that being said, 17 is the only correct answer.

• 4 weeks ago
Anonymous

>because most people subconsciously place implied multiplication over regular multiplication and division.
Most people being fuckwits is an argument for better education, not deliberately doing things wrong. What's next, cross multiplication is shit because most people only know dot multiplication?

• 4 weeks ago
Anonymous

Placing implied multiplication over regular multiplication and division leads to better readability.
>A/BC
Technically A would first be divided over B,
>Division and multiplication have the same precedence, so read from left to right
then multiply by C.

But its way more intuitive to do it the other way around.

• 4 weeks ago
Anonymous

>Placing implied multiplication over regular multiplication and division leads to better readability.
Not if you know how to read.
>But its way more intuitive to do it the other way around.
It's way more intuitive to go right to left?

• 4 weeks ago
Anonymous

>its way more intuitive to go right to left?
Thats not what I am saying.
I am saying that placing implied multiplication over regular multiplication and division is more natural.

Doesnt matter if its
>ABC
Or
>CAB
I believe AB should always be multiplied first in an ideal world

• 4 weeks ago
Anonymous

>I believe AB should always be multiplied first in an ideal world
What you believe doesn't really have any bearing on what is true. Fuck all about AB indicates it should be read before A÷B, AxB, or A*B.

You want to bitch about PEMDAS, bitch about fractions. ½ and 1÷2 aren't the same thing such that A÷½≠A÷1÷2.

• 4 weeks ago
Anonymous

>What you believe doesn't really have any bearing on what is true.
Yes it does. This is a notational convention, whatever we all say is true therefore is true.

3. 1 month ago
Anonymous

It's 17.

PEMDAS
>Parentheses
>Exponents
>Multiplication/Division

2+5(8-5)
2+5(3)
2+5*3
2+15
17

If you think the answer is anything else then the education system failed you and I would put money on you being American.

4. 1 month ago
Anonymous

5. 1 month ago
Anonymous

The misparsing that gives you 21 is a fairly common misconception with the kids I tutor. They don't realize the omitted multiplication sign between 5 and (8-5) is supposed to take priority over the 2+5.

6. 4 weeks ago
Anonymous

This isn't even fucking unclear.

• 4 weeks ago
Anonymous

if someone writes 1/ab then it means 1/(ab) because there's no point in writing b/a like that.
I don't care about your gay retarded rules you learned in middle school, I'm talking about real mathematical texts.

• 4 weeks ago
Anonymous

>I don't care about your gay retarded rules you learned in middle school
You mean "how to read and write basic arithmetic"
>I'm talking about real mathematical texts.
Sounds like the fuckwits writing that shit need to go back to middle school.

• 4 weeks ago
Anonymous

if someone writes 1/ab then it means 1/(ab) because there's no point in writing b/a like that.
I don't care about your gay retarded rules you learned in middle school, I'm talking about real mathematical texts.

1/ab is an interesting example because the intended meaning is clear, but it’s hard to write down a simple enough rule that small children and twitter users can follow

• 4 weeks ago
Anonymous

The rule is just PEMDAS. It's simple as fuck.

• 4 weeks ago
Anonymous

No, it is not; that is not the notation that actual mathematicians use. The notation that actual mathematicians use is a bit more subtle than that, and for that reason is generally only taught in simplified form to primary school students; but you would be wise not to confuse the lies-to-children simplification with the real thing.

• 4 weeks ago
Anonymous

Okay, you're picking a fight with google's built in calculator over how to do basic arithmetic.

You understand the google calculator wins that argument, right?

• 4 weeks ago
Anonymous

No, I do not. Please explain.

7. 4 weeks ago
Anonymous

2+5(8-5)
2+40-25
2+15
17

8. 4 weeks ago
Anonymous

>2+5*8-5
Obviously its 51

9. 4 weeks ago
Anonymous

2+5(8-5)
2+5(3)
2+53
55

10. 4 weeks ago
Anonymous

Public school educated American here, how exactly are you supposed to get 21?

• 4 weeks ago
Anonymous

(2+5)(8-5)

11. 4 weeks ago
Anonymous

2+5(8-5)
2+5*8-5*5
2+40-25
2+15
17

• 4 weeks ago
Anonymous

try using BODMAS correctly next time
2+5(8-5)
2+5*3
2+15
=17

• 4 weeks ago
Anonymous

>muh mnemonics
try not being a homosexual next time

12. 4 weeks ago
Anonymous

2 + 5(8-5)
7(8-5)
73

• 4 weeks ago
Anonymous

Pshhh!! Use order of operations dumbass!
2 + 5(8 - 5)
2 + 5(3)
2 + 53
55

13. 4 weeks ago
Anonymous

Watching the bait get worse as the iw of the board lowers is depressing. Back in my day the order of operations bait was actually ambiguous

• 4 weeks ago
Anonymous

No, I do not. Please explain.

https://en.wikipedia.org/wiki/Argument_from_authority

Also it helps that the calculator in question literally walks you through how to solve the problem step by step. So just look at that explanation.

• 4 weeks ago
Anonymous

Why would the google calculator have authority?

14. 4 weeks ago
Anonymous

Read any physics text book and 1/ab is assumed to be 1/(ab).

1/kT, p^2/2m, 1/2pi, etc

• 4 weeks ago
Anonymous

Physics textbooks tend to use horizontal fraction bars to denote division or otherwise use subscripts and superscripts and fractional slashes. The fuck physics book are you using that not only uses horizontally read division without fractions but also doesn't use a ÷ for that?

Also, how would a/b/c be read if they are doing that grouping bullshit, but aren't fucking using PEMDAS?

Literally the only times I've seen anything like what you described, the books in question had special notation guidelines that complete forbid you even writing shit like a/b/c and gave division and multiplication different priority completely.

And yeah, no shit you can use custom notation, but you have to fucking explain that and that's not going to be universally understood outside of materials associated with that fucking book.

Why would the google calculator have authority?

>Why would the google calculator have authority?

15. 4 weeks ago
Anonymous

something below or above 20 i think, x2 = 0 uncertain or smth

16. 4 weeks ago
Anonymous

2+5=7
8-5=3

7(3)=21

Obvious.