Math: right answer

[ghost recon]

no sir, the answer should be 288, simplify first numbers inside parenthesis then solve it from left to right, 48÷2=24 then 24x12=288.

hahaha

funny. marami pa naman error mga text books ngayon.

[digitalron]

http://mathforum.org/library/drmath/view/54341.html

As written, your expression ax/by should be evaluated left to right: a times x, divided by b, times y. The multiplication is not done before the division, but both are done in the order they appear.

Some texts make a rule, as in your second solution, that multiplication without a symbol ("implied multiplication") should be done before any other operations in an expression, including "explicit multiplication" using a symbol. Following this rule, you would multiply a by x, then multiply b and y, then divide one by the other. Some (probably most) texts don't mention such a rule - but some of those may use it without saying so, which is far worse.

I don't know of a general rule among mathematicians that implied multiplication should be done before explicit multiplication. As far as I'm concerned, all multiplications fit in the same place in the order of operations.

I notice a lot of people have misunderstood MDAS to strictly mean Multiply then Divide then Add then Subtract.

In reality, this should be read as (Multiply AND Divide) before (Add and Subtract).

This means that Multiplication and Division have the same level of importance, and evaluating an expression containing only multiplication and division operators is done left to right.


There are those who say that the expression 2(9+3) has an implied multiplication. Yes, that is correct. it is implied that 2 is multiplied by (9+3), and could thus be interpreted as 2*(9+3).

Some keep saying that in 2(9+3), we should recognize that the parenthesis expressions should be evaluated first. Correct! That is why 2(9+3) becomes 2(12).

Before 2(12), there is a 48÷ and some people say that since parenthesis operations should be done first, 2(12) should become 24. Well, 2(12) has the 2 beside the (12), yes, but the 2 is NOT INSIDE (12). 2(12) is simply 2*(12) or 2*12

Since the division operator came before the multiplication operator, it gets evaluated first. Again, I repeat, MDAS does not say that Multiplication has absolute precedence over Division. Mult and Div have the same level of precedence, to be evaluated from left to right.

48÷2(9+3) becomes

48÷2(12) becomes

48÷2*(12) becomes

48÷2*12

That last expression is then evaluated left to right because division came before multiplication. The result is 288.

And no, I did not flunk my math. I got 1.0 in many of them. And I took up stuff like Math 17, 53, 54, 55, 101, 114, and 150 among others.

[renzo_d10]

Isn't the 2(9+3) part of the denominator ?

48/2(9+3)
48/24
= 2 ?

__48__
2(9+3)

= 2 ?

[digitalron]

Isn't the 2(9+3) part of the denominator ?

48/2(9+3)
48/24
= 2 ?

To clarify, the equation 48÷2(9+3) or 48/2(9+3) can be described as an ambiguous expression because it is not clear what is the intent of the writer of the equation. the 2(9+3) COULD be the denominator, if there was a caveat statement provided. However, there is none, so we cannot simply imply that it is to be treated as such.

However, the ambiguity can be settled by following the PEDMAS/BIDMAS/BOMDAS/etc rule which clearly stipulates the order by which the operations should be performed.

That is why the Wolfram Alpha site treats the expression as a straightforward operation: http://www.wolframalpha.com/input/?i=48%2F2%289%2B3%29

That link shows how Wolfram Alpha, a very highly respected scientific resource, interprets the expression.

That is also why Google interprets the expression as a straightforward operation: http://www.google.com.ph/#hl=en&sour...71ec102408a304

[renzo_d10]

To clarify, the equation 48÷2(9+3) or 48/2(9+3) can be described as an ambiguous expression because it is not clear what is the intent of the writer of the equation. the 2(9+3) COULD be the denominator, if there was a caveat statement provided. However, there is none, so we cannot simply imply that it is to be treated as such.

However, the ambiguity can be settled by following the PEDMAS/BIDMAS/BOMDAS/etc rule which clearly stipulates the order by which the operations should be performed.

That is why the Wolfram Alpha site treats the expression as a straightforward operation: http://www.wolframalpha.com/input/?i=48%2F2%289%2B3%29

That link shows how Wolfram Alpha, a very highly respected scientific resource, interprets the expression.

That is also why Google interprets the expression as a straightforward operation: http://www.google.com.ph/#hl=en&sour...71ec102408a304

Okaaaaaaaay ....


Weird. :hysterical: Blame the writer. :lol:

BTW : You have a point. And you clearly stated why did you end up with 288. But nonetheless, I'd stick with my answer which is -284759 ... jk it's two.

[armscor40]

nice one TS, witty how simple high school math becomes complicated by giving algebraic equations for confusion, hehehe

anyway you solve it even how critical you are...there are 2 answers to this question...2 or 288 & there are lots of references to choose from as stated from the above posts...

sabi nga ni Shalani "ang sagot ay 2 na may 88 pala"...for me!

[yapoy86]

try nyo sa excel 288 din ang sagot...

[170kphlang]

kaya ayoko ng math talaga e, 2 or 288 hindi pa tayo nagkaka-sundo...

[dale323]

288 din ako. nagpustahan na din kami dito sa opis. hehehe.... and nanalo ang 288.

[niwde11]

i voted 2 coz i know it is. but i am an open minded person hehehe. i enjoy talking to people proving i am wrong.:D
so i'll monitor this thread from time to time. i even asked the opinion of my math wizard friend we often called "Euclid". if we are wrong, i will call my math teacher in NDGM and my math prof in MIT. sasabihin ko mam, mali pala akong napili nyo na taga check ng papel hahhaha.

[_Qwerty_]

sa excel kasi pag ni type mo mag e error sya.. tapos ginagawa nyang:

48/2*(9+3).. kaya nagiging 288

try nyo sa excel 288 din ang sagot...

[rene_tagle]

sa excel kasi pag ni type mo mag e error sya.. tapos ginagawa nyang:

48/2*(9+3).. kaya nagiging 288

kaya nag-error kasi alam ng excel na 48/2(9+3) ay magbibigay ng kalituhan sa mundo, kaya para wala na pinagtatalunan(at baka may magpatayan pa dahil dito)ginawa na nyang 48/2*(9+3) para wala nang away. kaya ang tamang sagot is 288.

[jansky]

kaya nag-error kasi alam ng excel na 48/2(9+3) ay magbibigay ng kalituhan sa mundo, kaya para wala na pinagtatalunan(at baka may magpatayan pa dahil dito)ginawa na nyang 48/2*(9+3) para wala nang away. kaya ang tamang sagot is 288.

48÷2*(9+3) = 288
48÷2*1(9+3) = 288

48÷2(9+3) = 2

taken here

V = W÷X(Y + Z)


and i'll stick to 2

[ghost recon]

hahaha pambihira....

again for those still in doubt that the answer is 2.

....One of the easiest ways to mess up an algebra problem is to solve things in the wrong order. Become very familiar with the order of operations, and make sure you always solve in the correct order. One way to help you remember the order of operations is to think of the sentence: "Please excuse my dear Aunt Sally." PEMDAS is the order of operations: parentheses, exponents, multiplication, division, addition and subtraction. Move from left to right when solving within a step.

so that's the rule. do not change the rule.

the phrase "move from left to right" simply instructs to look for the right order of operation which follows the rule of PEMDAS.

[Patti]

hahaha pambihira....

again for those still in doubt that the answer is 2.

....One of the easiest ways to mess up an algebra problem is to solve things in the wrong order. Become very familiar with the order of operations, and make sure you always solve in the correct order. One way to help you remember the order of operations is to think of the sentence: "Please excuse my dear Aunt Sally." PEMDAS is the order of operations: parentheses, exponents, multiplication, division, addition and subtraction. Move from left to right when solving within a step.

so that's the rule. do not change the rule.

the phrase "move from left to right" simply instructs to look for the right order of operation which follows the rule of PEMDAS.

Can you please state the PEMDAS rule so that everyone is clear about it?
And then, kindly explain how it is different from BODMAS.

[rene_tagle]

48÷2*(9+3) = 288
48÷2*1(9+3) = 288

48÷2(9+3) = 2

taken here

V = W÷X(Y + Z)


and i'll stick to 2

48÷2(9+3)=288

48÷[2(9+3)]=2

[ooba99]

I'm no math genius and my answer is 2.

[roninblade]

hahaha pambihira....

again for those still in doubt that the answer is 2.

....One of the easiest ways to mess up an algebra problem is to solve things in the wrong order. Become very familiar with the order of operations, and make sure you always solve in the correct order. One way to help you remember the order of operations is to think of the sentence: "Please excuse my dear Aunt Sally." PEMDAS is the order of operations: parentheses, exponents, multiplication, division, addition and subtraction. Move from left to right when solving within a step.

so that's the rule. do not change the rule.

the phrase "move from left to right" simply instructs to look for the right order of operation which follows the rule of PEMDAS.

hahaha! pambihira. people still don't backread other people's post before posting themselves. ;)

[kinyo]

my answer is 2

i read 2(9+3) as "2 is the coefficient of (9+3)" ... although the operation between 2 and (9+3) is indeed multiplication, the multiplication cannot be broken by PEMDAS rule because of the definition of 'coefficient' ... 2 mutiplied by (9+3) is a single quantity

the original expression 48÷2(9+3) is indeed ambiguous and i don't blame people giving 288 as the answer ... people used to writing mathematical expressions in a single line are aware of this and would never write such expression, they will add more parenthesis to remove the ambiguity

i would write 48÷(2*(9+3)) to get 2, or (48÷2)*(9+3) to get 288

in short ... it is a dumb question, so it gets dumb answers!

[rene_tagle]

hahaha pambihira....

again for those still in doubt that the answer is 2.

....One of the easiest ways to mess up an algebra problem is to solve things in the wrong order. Become very familiar with the order of operations, and make sure you always solve in the correct order. One way to help you remember the order of operations is to think of the sentence: "Please excuse my dear Aunt Sally." PEMDAS is the order of operations: parentheses, exponents, multiplication, division, addition and subtraction. Move from left to right when solving within a step.

so that's the rule. do not change the rule.

the phrase "move from left to right" simply instructs to look for the right order of operation which follows the rule of PEMDAS.

sir mukhang mali ata pagkakaintindi mo sa PEMDAS, ganito yan:

If the expression consists of parenthesis, exponents, +, –, × and ÷, then the operations MUST be performed in the following order.

Always work on the calculations within parenthesis first if any.
Next, calculate the exponents.
Then, carry out multiplication OR division, working from left to right.
Lastly, do addition OR subtraction, working from left to right.

marami ang hindi nakakapansin ng salitang OR dun sa rule ng PEMDAS, hindi po in order yung multiplication and division, pantay lang po ang priority nila, so kung ganun ang case dapat from left to right mo isolve ang problem.