Posted on 04/12/2011 1:32:09 PM PDT by grundle
Texas Instruments TI-85 says:
48÷2(9+3) = 2
But Texas Instruments TI-86 says:
48÷2(9+3) = 288
Multiplication and division are of equal precedence - left-to-right order of appearance dictates between them, absent any parenthesis.
The same for addition and subtraction.
Yep, good ol’ PEMDAS.
When I took my algebra classes many, many, many years ago, the mathematical order of operations first rule was to clear the parentheses. So you are left with 48 divided by 24, ergo the answer is 2.
Lol... :D I agree 100%.. as a matter of fact, I think programmers see a side of math even math majors (let alone minors.. age included) won’t understand ;)
Bikk
Um - the division symbol and the slash are the same operation, with the same precedence rules. You implicitly added parenthesis around 2(9+3) that don’t exist to come up with 2.
The answer is 288.
48/2(9+3) is evaluated just like several people have already said:
1. Parenthesis
2. Multiplication and division
3. Addition and subtraction
When the operators have the same precedence, solve from left to right.
Including the implied multiplication between the 2 and the parens gives 48/2*(9+3)
Solving —
Parens first gives: 48/2*12
Mult and div have same precedence, so work L to R: 24*12 = 288
Excel says so.
Google says so.
My HP50g says so.
C# says so.
JavaScript says so.
PHP says so.
The calculator which says 2 is wrong. So are the humans who agree with it. :-) If you believe it’s 2, do some research until you’re convinced otherwise, because 288 is the answer.
From PurpleMath.com:
“A common technique for remembering the order of operations is the abbreviation “PEMDAS”, which is turned into the phrase “Please Excuse My Dear Aunt Sally”. It stands for “Parentheses, Exponents, Multiplication and Division, and Addition and Subtraction”. This tells you the ranks of the operations: Parentheses outrank exponents, which outrank multiplication and division (but multiplication and division are at the same rank), and these two outrank addition and subtraction (which are together on the bottom rank). When you have a bunch of operations of the same rank, you just operate from left to right.”
TI-85 < TI-86They fixed the bug in the latter version of the device.
What’s a TI-8x”, some kind of new smartphone??
[2,288]
Problem solved.
Next question :^)
The distributive property of multiplication tells me that 2(9+3) = 2(9)+2(3) = 18+6 = 24. It is a single expression. It could be 2(a+b) or 2(x+y). The entire expression must be dealt with before the expression is used in the remainder of the equation.
Please thank your son for myself and the others here who have agreed that it is indeed 288 :)
Bikk
48
______________ = ?
2(9+3)
^^^^^^^ This is not the original problem. Rewriting it this way is incorrect.
Because of precedence rules, the correct representation of the original problem is:
48
— * (9 + 3)
2
I supervised guys that did what you did in the Army. Fact is, it has nothing to do with this problem.
“What rule tells you the 2 and the (9+3) are inseparable?”
2(9+3) = (2*9) + (2*3)
basic algebra
What places the multiplication above the division in precedence? According to the rules of precedence I learned, as well as all those I have been able to find online, they are equal and are processed left-to-right?
That is the crux of the discussion here, of course.
Fun, isn’t it?
Multiplication and division are of equal precedence - left-to-right order of appearance dictates between them, absent any parenthesis. The same for addition and subtraction.
“The entire expression must be dealt with before the expression is used in the remainder of the equation.”
Negative, GhostRider.
48/2(9+3)
The operations inside the parens are evaluated first to give 48/2*12
Because mult and div are of equal precedence, the problem is then evaluated from left to right: 24 * 12 = 288.
Except that the 2 is preceded by “48/”.
If the 2(9+3) was the whole equation, then there would be no discussion over precedence.
“48
______________ = ?
2(9+3)
^^^^^^^ This is not the original problem. Rewriting it this way is incorrect.
Because of precedence rules, the correct representation of the original problem is:
48
— * (9 + 3)”
Never solved many quadratic equations have you?
I think that us old guys, read pre calculator, have a better handle on this......
All others, who think the answer is 288, are either RINOs or Trolls :)
2
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