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Re: the original OP:
It is absolutely, incontrovertibly right that the burden is on the person writing the mathematical statement to ensure that it is unambiguous. Parentheses is an available mechanism that removes ambiguity, which is why parentheses exist as a mathematical symbol. You cannot write an ambiguous statement, and then expect interpreters to agree unanimously with what you wanted them to think when you wrote it ambiguously.
This doesn't work, because when solving for a variable, you cannot divide by that same variable on both sides. This is not allowable in Algebra.
Don't want to read through 20 pages of comments...
I have an Aerospace Engineering Degree from an ABET accredited University, and a Minor in Mathematics.
No offense, but those who got 288 do their math at a grade school level.
Substitue 2 for x, then solve it that way.
48÷2(9+3) =48÷x(9+3)
48÷x(9+3) =48÷9x+3x
48÷9x+3x=48÷12x
48÷12x=48÷12(2)
48÷12(2)=48÷24
=2
On a serious note, who ever came up with this poorly written equation deserves to be smacked in the face with a calculus book.
I'm going to blow some minds or **** some grade school mathematicians off by saying 12÷2÷2=12.
Don't want to read through 20 pages of comments...
I have an Aerospace Engineering Degree from an ABET accredited University, and a Minor in Mathematics.
No offense, but those who got 288 do their math at a grade school level.
Substitue 2 for x, then solve it that way.
48÷2(9+3) =48÷x(9+3)
48÷x(9+3) =48÷9x+3x
48÷9x+3x=48÷12x
48÷12x=48÷12(2)
48÷12(2)=48÷24
=2
On a serious note, who ever came up with this poorly written equation deserves to be smacked in the face with a calculus book.
I'm going to blow some minds or **** some grade school mathematicians off by saying 12÷2÷2=12.
Don't want to read through 20 pages of comments...
I have an Aerospace Engineering Degree from an ABET accredited University, and a Minor in Mathematics.
No offense, but those who got 288 do their math at a grade school level.
Substitue 2 for x, then solve it that way.
48÷2(9+3) =48÷x(9+3)
48÷x(9+3) =48÷9x+3x
48÷9x+3x=48÷12x
48÷12x=48÷12(2)
48÷12(2)=48÷24
=2
On a serious note, who ever came up with this poorly written equation deserves to be smacked in the face with a calculus book.
I'm going to blow some minds or **** some grade school mathematicians off by saying 12÷2÷2=12.
Put that in your pipe and smoke it.
I don't see the point of mentioning your education.... Many of us here are educated as well. Yours is not impressive without mentioning the actual school. I have a computer science degree from a small private university here in NJ if that helps define my qualifications.
The part where you make a mistake is forgetting that division is inverse multiplication. So when you distribute X, you should really be distributing 1/x.
48÷2(9+3) =48÷x(9+3)
48÷2(9+3) =48÷x*(9+3)
48÷x(9+3) =48*1/x*(9+3)
48÷x(9+3) =48*9(1/x)+3(1/x)
and do on.
This way ensures that you follow the order of operations. It's alright though, many people don't remember basic math.
I don't see the point of mentioning your education.... Many of us here are educated as well. Yours is not impressive without mentioning the actual school. I have a computer science degree from a small private university here in NJ if that helps define my qualifications.
You're right, my education is irrelevant. Didn't intend for it to sound impressive either. I just wanted to point out that I'm not an internet MBA because they are so prevalent everywhere (including online) today.
Quote:
Originally Posted by NJBest
The part where you make a mistake is forgetting that division is inverse multiplication. So when you distribute X, you should really be distributing 1/x.
48÷2(9+3) =48÷x(9+3)
48÷2(9+3) =48÷x*(9+3)
48÷x(9+3) =48*1/x*(9+3)
48÷x(9+3) =48*9(1/x)+3(1/x)
and do on.
This way ensures that you follow the order of operations. It's alright though, many people don't remember basic math.
I follow you with the inverse multiplication, but I lose you in two places. First is the * you threw in right before the bracket. I know what you mean, but it's already implied, so it's not necessary. I don't know why you did that.
Second is when you don't keep the (9+3) in the denominator when you do the inverse. It should be 48*1/(9x+3x), which is 48/12x, you wouldn't change that to 48/12*x, would you????
Also just a thought, your logic works with 9÷3, which can be expressed as 9*1÷3, the answer is still three but it doesn't work all the time.
If 9*3 can be expressed as 9÷1÷3, then why is it still three, and not 27?
Your logic works with 9÷3, but not with 9*3.
Don't want to read through 20 pages of comments...
I have an Aerospace Engineering Degree from an ABET accredited University, and a Minor in Mathematics.
No offense, but those who got 288 do their math at a grade school level.
Grade school math is all that is needed for this simple equation.
Typical engineer; taking something that is simple, and over complicating it to the point of failure.
Let's take it back to grade school shall we?
48/2(9+3)=?
Step one: solve inside parentheses: 48/2*12=?
Step two: Solve exponents... No exponents, so proceed to step three.
Step three: solve multiplication and division from left to right: 48/2 is 24, 24*12 = 288 The ONLY way to get it wrong is to ignore this rule and multiply 2 and 12 together first, THEN do the division. Since it doesn't say to do multiplication first, then do the division; to do so is ignoring one of the basic building blocks of all mathematics. If you toss out the rules and foundation laid down by "grade school math" then you should toss out all mathematics as a free-for-all in which anyone, can do anything, in any order, just to arrive at whatever solution they want.
You're right, my education is irrelevant. Didn't intend for it to sound impressive either. I just wanted to point out that I'm not an internet MBA because they are so prevalent everywhere (including online) today.
I follow you with the inverse multiplication, but I lose you in two places. First is the * you threw in right before the bracket. I know what you mean, but it's already implied, so it's not necessary. I don't know why you did that.
Second is when you don't keep the (9+3) in the denominator when you do the inverse. It should be 48*1/(9x+3x), which is 48/12x, you wouldn't change that to 48/12*x, would you????
I put in the * before the bracket to make the implied multiplication obvious. Typically, I wouldn't put it in, but for demonstration purposes I did.
The second place where you lose me is precisely where your math goes wrong. Nothing in the equation says that the portion in the parenthesis is part of the divisor.
Also just a thought, your logic works with 9÷3, which can be expressed as 9*1÷3, the answer is still three but it doesn't work all the time.
If 9*3 can be expressed as 9÷1÷3, then why is it still three, and not 27?
Your logic works with 9÷3, but not with 9*3.
That's because I left out parenthesis in my previous post. Fixed below.
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