48÷2 (9+3) argument

milomak said:
they ****ed you up
Click to expand...

sure fuccked me up till pass varsity maths:) - or I was taught right :), my old school text books still say the exact same in any case. (they are as old as the ages btw).
 
5
---
3(x+y)

or

5÷3(x+y)

i can't imagine many maths teachers saying solve 5÷3 before (x+y)
 
X = a÷b(c+d) The issue here is whether the term (c+d) is being multiplied by (b) or by (a÷b). However, brackets always come first, so we first solve b(c+d) before we even look at the a. Thus:

X = a÷(bc+bd)

a = 48
b = 2
c = 9
d = 3

X = 48÷[(2)(9)+(2)(3)]

= 48÷24

= 2
 
zulgin said:
sure fuccked me up till pass varsity maths:) - or I was taught right :), my old school text books still say the exact same in any case. (they are as old as the ages btw).
Click to expand...

and i happened to do maths at varsity. so do i win the prize?
 
MiY4Gi said:
X = a÷b(c+d) The issue here is whether the term (c+d) is being multiplied by (b) or by (a÷b). However, brackets always come first, so we first solve b(c+d) before we even look at the a. Thus:

X = a÷(bc+bd)

a = 48
b = 2
c = 9
d = 3

X = 48÷[(2)(9)+(2)(3)]

= 48÷24

= 2
Click to expand...

your maths assumes a to be the numerator

288 favours assume the numerator to be (a/b). yet the original post does not mention that there should be a bracket around a/b. and this is where they fall short. they add a bracket.

they fail to understand when you add a bracket, you have a different equation/. I ask them to challenge that they have changed the equation.
 
oh ffs can't believe i missed this

2(9+3)
is actually
(2)(9+3)
so when the brackets are completed you have
24

edit - missed it in terms of explantion. not in terms of understanding.
 
You have to eliminate the brackets entirely first.

48÷2(9+3)
=48÷2(12)

bracket is still there so deal with bracket first before division. Yes the bracket implies multiplication but it's still a bracket.

=48÷24
=2
 
For everyone saying the answer is 288, what is the answer to 5/(5) and 5/5?

If you're saying the answer to the OP is 288 then 5/(5) would be 25... wrong.
 
SaiyanZ said:
For everyone saying the answer is 288, what is the answer to 5/(5) and 5/5?

If you're saying the answer to the OP is 288 then 5/(5) would be 25... wrong.
Click to expand...

I should point out that (5) = 1(5) which is true but by their logic (the people who think it is 288):
5/(5)
= 5 / 1(5)
= 5 / 1 * (5)
= 5 * 5
= 25

And that's why I still maintain the answer is 2..

//Still can't believe this thread is going on... Best troll thread of all time :twisted:
 
I saw this link in the thread. It explains everything and why the answer is 2.

http://www.purplemath.com/modules/orderops2.htm

This next example displays an issue that almost never arises but, when it does, there seems to be no end to the arguing.

Simplify 16 ÷ 2[8 – 3(4 – 2)] + 1.
16 ÷ 2[8 – 3(4 – 2)] + 1
= 16 ÷ 2[8 – 3(2)] + 1
= 16 ÷ 2[8 – 6] + 1
= 16 ÷ 2[2] + 1 (**)
= 16 ÷ 4 + 1
= 4 + 1
= 5

The confusing part in the above calculation is how "16 divided by 2[2] + 1" (in the line marked with the double-star) becomes "16 divided by 4 + 1", instead of "8 times by 2 + 1". That's because, even though multiplication and division are at the same level (so the left-to-right rule should apply), parentheses outrank division, so the first 2 goes with the [2], rather than with the "16 divided by". That is, multiplication that is indicated by placement against parentheses (or brackets, etc) is "stronger" than "regular" multiplication.
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abzo said:
You have to eliminate the brackets entirely first.

48÷2(9+3)
=48÷2(12)

bracket is still there so deal with bracket first before division. Yes the bracket implies multiplication but it's still a bracket.

=48÷24
=2
Click to expand...

this is where you are wrong, yes you have to eliminate the brackets first however!

it is not 2(9+3) but 1÷2(9+3)

1÷2(9+3)(48) should give you the same answer not?

xyz = zxy if not then you are doing something wrong, hence the 2 in 1÷2 is actually 2^(-1)
 
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nakedpeanut said:
I should point out that (5) = 1(5) which is true but by their logic (the people who think it is 288):
5/(5)
= 5 / 1(5)
= 5 / 1 * (5)
= 5 * 5
= 25

And that's why I still maintain the answer is 2..

//Still can't believe this thread is going on... Best troll thread of all time :twisted:
Click to expand...

1/(5) still remains the denominator, if you put a one in there you have to put the entire brackets around it otherwise you are changing a basic element of mathematics..

there are 4 elements in mathematics,
plus
minus
divide
multiply

you may not interchange these at all by making 1/2 = 2.
 
MiY4Gi said:
X = a÷b(c+d) The issue here is whether the term (c+d) is being multiplied by (b) or by (a÷b). However, brackets always come first, so we first solve b(c+d) before we even look at the a. Thus:

X = a÷(bc+bd)

a = 48
b = 2
c = 9
d = 3

X = 48÷[(2)(9)+(2)(3)]

= 48÷24

= 2
Click to expand...

This is where you all have lost the plot, division doesn't change the term into one two terms, terms can only be split via subtraction or addition, and any elements within a term should be interchangeable, hence

1/2 is an element itself and NOT 2.

hence the tree terms are
(48)(0.5)(9+3)...it still remains one term, you can swap either of these tree around and the answer should remain the same, because they are 3 separate elements. if you can't get the same answer by swapping them then you are doing something wrong.
 
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Zulgin, read my last post. You can't add any new brackets and interchange terms. You can only do that if there were brackets around each figure (or if there were no brackets at all).The best way to answer a question like this is to make all the brackets go bye-bye and then do any division, multiplication etc.
 
SaiyanZ said:
Zulgin, read my last post. You can't add any new brackets and interchange terms. You can only do that if there were brackets around each figure (or if there were no brackets at all).The best way to answer a question like this is to make all the brackets go bye-bye and then do any division, multiplication etc.
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you can't make a denominator a numerator, which is what you are trying to do. :)

1/2(9+3) = (9+3)/2

you need to make all the brackets go bye bye yes, however a fraction has an algorithm which needs to be solved first the (9+3) is outside the algorithm.

its the same as sin180(3+4)

the sign algorithm has to be solved first
 
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?

1/2(9+3) = (9+3)/2

If you're saying that that is half times (9+3) then your're correct. If it is 1 divided by 2 into (9+3) then you're not.
 
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