Question 1150813: 8÷2(2+2)
Found 3 solutions by Alan3354, MathTherapy, greenestamps:
Answer by Alan3354(69443)   (Show Source):
You can put this solution on YOUR website! Try it.
I'll check your work.
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I'll do a similar problem.
63 ÷ 3(4+3)
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Add the numbers in the parentheses.
63 ÷ 3*7
Multiply
63 ÷ 21
= 3
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Another opinion posted.
Figuring out which is right and which is wrong is educational.
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Hint: it's a matter of order, or lack of parentheses.
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After some further thought:
8÷2(2+2) ---> (8/2)*(2+2) = 16
Or,
8/(2*(2+2)) = 8/8 = 1
I don't think the "left to right" resolves the ambiguity.
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During 4 semesters of HS algebra, 2 semesters of college calculus, 1 semester of Diff Eqns and then "Advanced Math for Engineers" I never heard anything about "left to right."
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IDK when "left to right" became a rule.
And, the "left to right" violates PEMDAS by Dividing before Multiplying.
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I think it was 4 semesters of college calculus. Been a while, not certain.
Answer by MathTherapy(10552)  (Show Source):
You can put this solution on YOUR website!
8÷2(2+2)
I agree with @ALAN that you need to try to do the problem yourself, but if you follow his instructions to simplify a
similar problem, your answer will be INCORRECT. As a matter of fact, the correct answer for his example is 147, NOT 3.
Answer by greenestamps(13200)  (Show Source):
You can put this solution on YOUR website!
In the given expression, in the part "2(2+2)" there is an implied multiplication. An expression written just before a set of parentheses without showing any operator symbol means there is a multiplication there. So rewrite the expression as "8÷2*(2+2)"
Then....
PEMDAS:
(1) Parentheses
(2) Exponents
(3) Multiplication and Division, left to right
(4) Addition and Subtraction, left to right
In your example...
(1) There is an expression in parentheses; simplify it first
(2) There are no exponents
(3) All that is left is multiplication and division; perform those operations in order, left to right
Tutor @MathTherapy is right -- in the example shown by the other tutor the multiplication and division are NOT done left to right, as required....
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