4-2^2+5x3-2=11

[dodgyviper]

jet_noise said:

Implied operator again. Is that in or outside the "rules"?

Even if allowed, it means the (4-2^2)+ has to come to 41.

Either this maths teacher is going to take me down an educational route I've never been before, or I'm gonna break out my best Paddington bear stare

[V8LM]

ash73 said:

Assuming (x) = -x

((4) - 2^2 + 5) x 3 - 2 = (11)

(-4 - 4 + 5) x 3 - 2 = -11

-3 x 3 - 2 = -11

Nearly:

(((4) - 2^2 + 5)) x 3 - 2 = (11)

((-4 - 4 + 5)) x 3 - 2 = -11

((-3)) x 3 - 2 = -11

(3) x 3 - 2 = -11

-3 x 3 - 2 = -11

Edited by V8LM on Saturday 13th October 14:38

[JonChalk]

ash73 said:

Assuming (x) = -x

What? I mean yes, that assumption works, but......WTF?

Is that a proper, defined use of brackets?

[ben5575]

OP I hope your son is going to take an ipad into class on Monday and show them this thread and the grief it's caused for far too many grown men??

[gothatway]

chemistry said:

Here’s the original question; note there’s a bag of sweets resting on this...

OP originally misquoted the question, saying that it had to be "correct". The question says "true". Are we talking boolean logic here - e.g. 2=11 is False ? I have no time at the mo to look further - hedges to cut before it rains !

[JonChalk]

.....so the same bracket set () is doing two different jobs in that equation, with no specific, given way of telling what the brackets role is at a certain time??

Surely that's incredibly poor "mathematics" and a trick question bearing no relation to how that would have been applied in the real world, or indeed expressed in a properly formal way?

Shoddy, lazy teaching if you ask me - the point of brackets is to bring a logical order of calculation to complex calculations - all this does is confuse someone who doesn't (yet, maybe) have the experience to see when they are being "had".

[V8LM]

JonChalk said:

.....so the same bracket set () is doing two different jobs in that equation, with no specific, given way of telling what the brackets role is at a certain time??

Surely that's incredibly poor "mathematics" and a trick question bearing no relation to how that would have been applied in the real world, or indeed expressed in a properly formal way?

Shoddy, lazy teaching if you ask me - the point of brackets is to bring a logical order of calculation to complex calculations - all this does is confuse someone who doesn't (yet, maybe) have the experience to see when they are being "had".

It's redefining what the bracket means. And no, it isn't done.

You could do anything: (x) = 0 or (x) = x/x or ....

Edited by V8LM on Saturday 13th October 15:51

[FredClogs]

gothatway said:

chemistry said:

Here’s the original question; note there’s a bag of sweets resting on this...

OP originally misquoted the question, saying that it had to be "correct". The question says "true". Are we talking boolean logic here - e.g. 2=11 is False ? I have no time at the mo to look further - hedges to cut before it rains !

I did wonder if the answer may be given as binary... But that would be 3 anyway, which still doesn't seem to work.

I think boolean logic is a bit above year 9, perhaps its a school for the gifted kids, or daft teachers.

[V8LM]

ash73 said:

It's a convention used by accountants to represent negative numbers.

OP will let us know, but in the meantime pass the choccy buttons

To share (you were a pair of brackets missing)

[V8LM]

ash73 said:

V8LM said:

((you were a pair of brackets missing))

EFA

[gothatway]

GOT IT !!!

(4-2)^2+5x(3-2) =11

.
.
.
.
.
.

In base 8.


Get your son to pas that on to the teacher, and we can share the sweeties.

[JonChalk]

gothatway said:

GOT IT !!!

(4-2)^2+5x(3-2) =11

.
.
.
.
.
.

In base 8.


Get your son to pas that on to the teacher, and we can share the sweeties.

That's way neater and tidier an explanation than the tenuous multiple-definition brackets idea (not that poster's fault, I mean, though - it's a solution, just a messy one).

[chemistry]

That is genius!!!!!

[V8LM]

ash73 said:

gothatway said:

In base 8.

Elegant, sweeties are yours I think!

[LordGrover]

gothatway said:

GOT IT !!!

(4-2)^2+5x(3-2) =11

.
.
.
.
.
.

In base 8.


Get your son to pas that on to the teacher, and we can share the sweeties.

You beat me to it.

I picked up the again thread this morning and after reading this post:

FredClogs said:

I did wonder if the answer may be given as binary... But that would be 3 anyway, which still doesn't seem to work.

I think boolean logic is a bit above year 9, perhaps its a school for the gifted kids, or daft teachers.

... I'd seen the mention of binary which set me thinking about a different base.

Nicely done gothatway!

[chemistry]

Brilliant stuff folks, thank you all! Next steps...

Firstly, whilst I don't think this is the answer the teacher had in mind, it's undoubtedly correct in every literal sense. So, my son will email his teacher today to submit this revised answer (admitting that he's had a bit of help). I'll let you now what the teacher says!

Secondly, this has been a great opportunity to teach my son about bases (not something he's covered, other than binary at a rudimentary level as part of Computer Science). He's now got his head around base 8 (and bases in general), so from that point of view alone, this process has been educational.

Thirdly, please don't be too hard on his teacher! If there's a typo then it will have been an honest mistake and if there's a trick it will be revealed in a good natured way. My son likes his maths teacher and he's inspired him to work hard...including on problems like this one!

Lastly, gothatway thank you in particular for providing me with a solution which, whatever the 'official' answer is, is definitely mathematically correct and allows me to mentally consider this problem solved If you PM me your address I'll send you a bag of buttons myself, or if you'd prefer, nominate a charity and I'll send them £10 on your behalf as a small token of my appreciation.

I'm grateful for everyone's efforts and as promised, I'll let you know what the teacher's official answer is as soon as I know it.

chemistry

[JuanCarlosFandango]

If that is the answer, I will shut the hell up about declining educational standards and how much tougher it was in my day.

[Strudul]

gothatway said:

GOT IT !!!

(4-2)^2+5x(3-2) =11

.
.
.
.
.
.

In base 8.


Get your son to pas that on to the teacher, and we can share the sweeties.

Not the "correct" answer though because:

chemistry said:

The good news is that he's provided a hint; that brackets are involved on both sides of the equation

[FredClogs]

Indeed and no one writes down numbers in octal without specifically specifying that that's what theyve done.

[gothatway]

chemistry said:

Brilliant stuff folks, thank you all! Next steps...

Firstly, whilst I don't think this is the answer the teacher had in mind, it's undoubtedly correct in every literal sense. So, my son will email his teacher today to submit this revised answer (admitting that he's had a bit of help). I'll let you now what the teacher says!

Secondly, this has been a great opportunity to teach my son about bases (not something he's covered, other than binary at a rudimentary level as part of Computer Science). He's now got his head around base 8 (and bases in general), so from that point of view alone, this process has been educational.

Thirdly, please don't be too hard on his teacher! If there's a typo then it will have been an honest mistake and if there's a trick it will be revealed in a good natured way. My son likes his maths teacher and he's inspired him to work hard...including on problems like this one!

Lastly, gothatway thank you in particular for providing me with a solution which, whatever the 'official' answer is, is definitely mathematically correct and allows me to mentally consider this problem solved If you PM me your address I'll send you a bag of buttons myself, or if you'd prefer, nominate a charity and I'll send them £10 on your behalf as a small token of my appreciation.

I'm grateful for everyone's efforts and as promised, I'll let you know what the teacher's official answer is as soon as I know it.

chemistry

I don't for one moment believe that mine is the expected answer (as pointed out - no brackets on the RHS - which I suspect is incorrect anyway, and no mention of number base which would therefore default to decimal), but if it has helped and particularly if it has enabled your son to investigate number bases, then that is fantastic. I think numeracy is incredibly important, so if you or anyone else wants to make a donation then look no further than National Numeracy.