dockeryfan Posted April 13, 2011 Share Posted April 13, 2011 I don't believe that it does. I think people are just tricked by it. You don't think this implies a numerator and a denominator? 8x² ÷2x =1 Link to comment Share on other sites More sharing options...
Tweedr01 Posted April 13, 2011 Share Posted April 13, 2011 Exactly my point. You shouldn't have to determine that two equations by deducing anything! (btw you are making a lot of assumptions with those parentheses that are wrong but that's kind of the point) The "÷" makes it complete bullcrap mathematically. If 2x is a number, I can reduce it any which way. You are wrong, because that number CAN be reduced independently. That's what is great about math. But with a "÷" you are limited, and you cannot. So the answer is that you have to treat this like a 2nd grader. There is no other way.EDIT Oh wait. I see what you are saying about them being 2 different equations. But the REASON was that the "÷" is AMBIGUOUS. It IMPLIES a numerator and a denominator, but one really is not there. Answer has to be 288. But that's because the stupid "÷" HA gotcha, ---------- Post added April-13th-2011 at 10:43 AM ---------- You don't think this implies a numerator and a denominator? 8x² ÷2x =1 nah, it's tricky but no different from / again, don't try to overanalyze it, #1 mistake in math, it's probably more simple than you think it is Link to comment Share on other sites More sharing options...
SonOfWashington Posted April 13, 2011 Share Posted April 13, 2011 You don't think this implies a numerator and a denominator? 8x² ÷2x =1 It would lead some people to believe that 2x is the divisor, but if you write it like this: 8 * x^2 / 2 * x = 1 which is the exact same thing, then it's easier to see that it is not the case. Link to comment Share on other sites More sharing options...
HailGreen28 Posted April 13, 2011 Share Posted April 13, 2011 And the vote tally is closer than ever, LOL. Either way, about half the people voting in this forum are wrong. So much for our intelligence. :doh: btw - as the equation is written, the answer's still 288. Link to comment Share on other sites More sharing options...
dockeryfan Posted April 13, 2011 Share Posted April 13, 2011 It would lead some people to believe that 2x is the divisor, but if you write it like this:8 * x^2 / 2 * x = 1 which is the exact same thing, then it's easier to see that it is not the case. You realize that you just wrote: 8 * x^2 ---------- = 1 2 * x The whole "÷" is the root of the problem. Link to comment Share on other sites More sharing options...
DjTj Posted April 13, 2011 Share Posted April 13, 2011 Here's a great image from the Hong Kong forum: http://www.hkttl.com/~hkgolden/?p=v&id=2952513&page=9 Link to comment Share on other sites More sharing options...
SonOfWashington Posted April 13, 2011 Share Posted April 13, 2011 You realize that you just wrote:8 * x^2 ---------- = 1 2 * x The whole "÷" is the root of the problem. I didn't.8 * x^2 ---------- * x = 1 2 is what I wrote. Again, the division symbol doesn't imply everything after it is the denominator. Just as a * b + c -d - e + f doesn't imply that a is multiplied by b + c - d - e + f. In other words, a * b + c -d - e + f =/= a * (b + c - d - e + f) as a / b + c - d - e + f =/= a / (b + c - d - e + f) Link to comment Share on other sites More sharing options...
Tweedr01 Posted April 13, 2011 Share Posted April 13, 2011 You realize that you just wrote:8 * x^2 ---------- = 1 2 * x The whole "÷" is the root of the problem. it might be the reason people are being confused, but if you use proper math it is no different than using a / Link to comment Share on other sites More sharing options...
dockeryfan Posted April 13, 2011 Share Posted April 13, 2011 it might be the reason people are being confused, but if you use proper math it is no different than using a / Again, the division symbol doesn't imply everything after it is the denominator. OK fine about that one but the "/" ???? ooooo, I'm not so sure about that one at all. Any math teachers want to weigh in on that one? Does this imply that both 2 and x are in the denominator? 8 * x^2 / 2 * x = 1 I think it absolutely does. Link to comment Share on other sites More sharing options...
Titaw Posted April 13, 2011 Share Posted April 13, 2011 I can't believe this thread still has legs: PLEASE everyone solve these two problems: 48/x(9+3) = 288 48/x(9+3) = 2 The ONLY time x = 2 is when the problem is equal to 288. Therefore the correct answer is 288. Link to comment Share on other sites More sharing options...
Tweedr01 Posted April 13, 2011 Share Posted April 13, 2011 Again, the division symbol doesn't imply everything after it is the denominator.OK fine about that one but the "/" ???? ooooo, I'm not so sure about that one at all. Any math teachers want to weigh in on that one? Does this imply that both 2 and x are in the denominator? 8 * x^2 / 2 * x = 1 I think it absolutely does. ? I don't disagree with that, as long as you concur that 8 belongs in the numerator as well EDIT: as long as you have the multiplication symbol at the end and no parentheses it does mean it is in the denominator after the / you have 2 * x, which IS 2x, unless you have them separated by a parentheses Link to comment Share on other sites More sharing options...
dockeryfan Posted April 13, 2011 Share Posted April 13, 2011 I can't believe this thread still has legs: PLEASE everyone solve these two problems:48/x(9+3) = 288 48/x(9+3) = 2 The ONLY time x = 2 is when the problem is equal to 288. Therefore the correct answer is 288. yeah, we're beyond that now Titaw. Answer is 288. (but ironically, not for the equations that you are writing) ---------- Post added April-13th-2011 at 11:12 AM ---------- It would lead some people to believe that 2x is the divisor, but if you write it like this:8 * x^2 / 2 * x = 1 which is the exact same thing, then it's easier to see that it is not the case. You realize that you just wrote:8 * x^2 ---------- = 1 2 * x The whole "÷" is the root of the problem. it might be the reason people are being confused, but if you use proper math it is no different than using a / ? I don't disagree with that, as long as you concur that 8 belongs in the numerator as wellEDIT: as long as you have the multiplication symbol at the end and no parentheses it does mean it is in the denominator after the / you have 2 * x, which IS 2x, unless you have them separated by a parentheses I'm pretty sure you are contradicting yourself here. ---------- Post added April-13th-2011 at 11:14 AM ---------- wait I just multiquoted 2 different people. I think the post just blew a gasket. Link to comment Share on other sites More sharing options...
Tweedr01 Posted April 13, 2011 Share Posted April 13, 2011 I'm pretty sure you are contradicting yourself here.---------- Post added April-13th-2011 at 11:14 AM ---------- wait I just multiquoted 2 different people. I think the post just blew a gasket. nope no contradictions, maybe you are referring to another poster? i think the post is confusing as heck sometimes just because it's difficult to phsycially type in what you mean, you know what i mean? Link to comment Share on other sites More sharing options...
Mufumonk Posted April 13, 2011 Share Posted April 13, 2011 yeah, we're beyond that now Titaw. Answer is 288. (but ironically, not for the equations that you are writing)---------- Post added April-13th-2011 at 11:12 AM ---------- I'm pretty sure you are contradicting yourself here. ---------- Post added April-13th-2011 at 11:14 AM ---------- wait I just multiquoted 2 different people. I think the post just blew a gasket. You tried to divide by zero, didn't you? Link to comment Share on other sites More sharing options...
dockeryfan Posted April 13, 2011 Share Posted April 13, 2011 nope no contradictions, maybe you are referring to another poster? i think the post is confusing as heck sometimes just because it's difficult to phsycially type in what you mean, you know what i mean? So then you agree that everything after the / is in the denominator? Because that is what I am saying. 8 * x^2 / 2 * x = 1 I'm saying that the / and the sign for division are not treated the same Link to comment Share on other sites More sharing options...
SonOfWashington Posted April 13, 2011 Share Posted April 13, 2011 I'm saying that the / and the sign for division are not treated the same I see where you're coming from here. I'm pretty sure though that they ARE the same, but I'd like someone to confirm that. Link to comment Share on other sites More sharing options...
mcsluggo Posted April 13, 2011 Share Posted April 13, 2011 I see where you're coming from here. I'm pretty sure though that they ARE the same, but I'd like someone to confirm that. theay ARE treated teh same.... but the y are NOT percieved the same. (and that is the same case with a(b+c) versus a*(b+c)) that is the problem. The correct answer to the equation is 288. Period. the original person who wrote the equation could've (should've) expressed it in a manner that eliminated PERCEIVED ambiguities better. Period. Link to comment Share on other sites More sharing options...
Homercles82 Posted April 13, 2011 Share Posted April 13, 2011 Seriously guys? Seriously? Link to comment Share on other sites More sharing options...
Pwyl Posted April 13, 2011 Share Posted April 13, 2011 I see where you're coming from here. I'm pretty sure though that they ARE the same, but I'd like someone to confirm that. They're the same. Absolutely 100%. They're both symbols for the Division operation. And I have to laugh a bit at all the references to "implied division" or "implied multiplication". There are no implications. the operator * or / or(or ÷) all mean exactly what they say they mean. When you read 48/2*12 or 48÷2(12), it means exactly "forty-eight divided by 2 multiplied by 12". Of course, without a generally accepted order to perform those operations in, you can perform the operations in different orders and get different answers. That's where "Order of Operations" comes in. It's the generally accepted order in which to perform operations, so you always get the same result. The generally accepted order of operations is that a grouping of multiplication and/or division operations are evaluated from left to right. It should be eye-bleedingly obvious that, in the case of the equation we're looking at here, you perform the 48/2 operation first, and plug the results into the place in the previous step that "48/2" lived, giving you 24*12 to evaluate in the next step. so to recap: 48÷2 is exactly the same as 48/2. 2(12) is exactly the same as 2*12. (unless you can point to a published order of operations that states otherwise. purple math doesnt count, grego :pfft:) The inside of parenthetical groupings are evaluated first, and the results are plugged in where the grouping resided to create the new equation to be evaluated in the subsequent step. Link to comment Share on other sites More sharing options...
terrifNick21 Posted April 13, 2011 Share Posted April 13, 2011 There are 91 people who failed math in school. Link to comment Share on other sites More sharing options...
MattFancy Posted April 13, 2011 Share Posted April 13, 2011 There are 91 people who failed math in school. No I didn't! Link to comment Share on other sites More sharing options...
dockeryfan Posted April 13, 2011 Share Posted April 13, 2011 They're the same. Absolutely 100%.They're both symbols for the Division operation. Really. You sure about that? I'd like you to solve the following equation for x 8x²/ 2x = 1 Link to comment Share on other sites More sharing options...
Pwyl Posted April 13, 2011 Share Posted April 13, 2011 Really. You sure about that?I'd like you to solve the following equation for x 8x²/ 2x = 1 Yep I see what you're doing there without solving for x. If you're going to group 2x together and put it in the denominator, you're going to do that regardless of what the symbol for division is. You're thinking that it would be naturally written as: 8x² ---- =1 2x Evaluating polynomials introduces an expanded set of convention I think.Wiki's explanation(yeah yeah it's wiki sue me). Looks like the more normal usage of that type of equation is 8x² + 2x + 1 = 0. We naturally group the x nodes together, and seeing the equation you presented puts us into that same convention. However, that doesn't negate my assertion that ÷ and / are the same, although I will admit to a very slight muddying of the waters on where the conventions start and stop. I'll still maintain that for all-numerical evaluations, you follow order of operations, and isolating and solving for variables follows another convention. Link to comment Share on other sites More sharing options...
Thinking Skins Posted April 13, 2011 Share Posted April 13, 2011 I didn't.8 * x^2 ---------- * x = 1 2 is what I wrote. Again, the division symbol doesn't imply everything after it is the denominator. Just as a * b + c -d - e + f doesn't imply that a is multiplied by b + c - d - e + f. In other words, a * b + c -d - e + f =/= a * (b + c - d - e + f) as a / b + c - d - e + f =/= a / (b + c - d - e + f) I'm with you on this one! Link to comment Share on other sites More sharing options...
dockeryfan Posted April 13, 2011 Share Posted April 13, 2011 Yep I see what you're doing there without solving for x. If you're going to group 2x together and put it in the denominator, you're going to do that regardless of what the symbol for division is. no, I don't think so. I think if it were written 8x²/ 2x = 1 and 8x² ÷ 2x = 1 You could possibly make an argument that the second means this (8)(x²)(1/2)x = 1 with the whole order of operations argument But in my opinion the first one puts 2x in the denominator every time. Every time. That is what I am talking about and why " ÷ " is the culprit. Link to comment Share on other sites More sharing options...
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