BlueTaelon Posted September 12, 2012 Share Posted September 12, 2012 (edited) Given w = 10, what is the answer to w + (w – 12 ÷ 22 • 3) • 7 I got 73, the test said its wrong and the answer is 17 this did not C&P correctly, the 22 should be an exponent of 2 to the 2nd power Edited September 12, 2012 by BlueTaelon Quote Link to comment Share on other sites More sharing options...
Carrie12345 Posted September 12, 2012 Share Posted September 12, 2012 (edited) Well, I got 68.5460ish, so don't ask me! Are you sure it's copied correctly? Edited September 12, 2012 by Carrie1234 Quote Link to comment Share on other sites More sharing options...
Perry Posted September 12, 2012 Share Posted September 12, 2012 Well, I got 68.5460ish, so don't ask me! :iagree: Quote Link to comment Share on other sites More sharing options...
Ailaena Posted September 12, 2012 Share Posted September 12, 2012 Given w = 10, what is the answer to w + (w – 12 ÷ 22 • 3) • 7 I got 73, the test said its wrong and the answer is 17 Are you missing a set of parentheses? Because how you group the stuff in the existing parens will affect your answer. ((w-12)÷(22*3) or (w-(12÷22)*3) or (w-(12÷(22*3))) Assume L-R (after PEMDAS) in the middle and you get 68.5 or something like that, so still not a matching answer :tongue_smilie: Quote Link to comment Share on other sites More sharing options...
wapiti Posted September 12, 2012 Share Posted September 12, 2012 There is probably a typo in the question. Otherwise, the answer has a repeating decimal, 68.54. For the answer to be 17, given w=10, the parentheses must compute to 1. Quote Link to comment Share on other sites More sharing options...
Carrie12345 Posted September 12, 2012 Share Posted September 12, 2012 Are you missing a set of parentheses? Because how you group the stuff in the existing parens will affect your answer. ((w-12)÷(22*3) or (w-(12÷22)*3) or (w-(12÷(22*3))) Assume L-R (after PEMDAS) in the middle and you get 68.5 or something like that, so still not a matching answer :tongue_smilie: Can I just say I'm so excited to see I got the "wrong" problem "right"?! Quote Link to comment Share on other sites More sharing options...
Arcadia Posted September 12, 2012 Share Posted September 12, 2012 Assuming answer is 17, w + (w – 12 ÷ 22 • 3) • 7 = 17 Substituting w = 10, 10 + (10 – 12 ÷ 22 • 3) • 7 = 17 (10 – 12 ÷ 22 • 3) • 7 = 7 (10 – 12 ÷ 22 • 3) = 1 12 ÷ 22 • 3 = 9 which is not possible I got 68.5 too. Quote Link to comment Share on other sites More sharing options...
BlueTaelon Posted September 12, 2012 Author Share Posted September 12, 2012 Well, I got 68.5460ish, so don't ask me! Are you sure it's copied correctly? Yep, I did a cut and paste. C&P from the test Given w = 10, what is the answer to w + (w – 12 ÷ 22 • 3) • 7? (1 point) 73 66 23 17 Quote Link to comment Share on other sites More sharing options...
Carrie12345 Posted September 12, 2012 Share Posted September 12, 2012 Yep, I did a cut and paste. C&P from the test Given w = 10, what is the answer to w + (w – 12 ÷ 22 • 3) • 7? (1 point) 73 66 23 17 So how did you work the answer to not include a decimal? The first step is 12/22. Quote Link to comment Share on other sites More sharing options...
BlueTaelon Posted September 12, 2012 Author Share Posted September 12, 2012 umm... a duh moment 22 should be 2 to the 2nd power. Don't know how to write that here Quote Link to comment Share on other sites More sharing options...
Kate in Arabia Posted September 12, 2012 Share Posted September 12, 2012 (edited) Oh, that makes all the difference! lol I got 17 10+(10-12÷2²x3)x7 10+(10-12÷4x3)x7 10+(10-3x3)x7 10+(10-9)x7 10+1x7 10+7 17 Edited September 12, 2012 by Kate in Arabia Quote Link to comment Share on other sites More sharing options...
BlueTaelon Posted September 12, 2012 Author Share Posted September 12, 2012 Oh, that makes all the difference! lol I got 17 ok, if you divide first I can see how you get 17 but order of operations says you multiply before dividing I thought. Quote Link to comment Share on other sites More sharing options...
vonfirmath Posted September 12, 2012 Share Posted September 12, 2012 (edited) umm... a duh moment 22 should be 2 to the 2nd power. Don't know how to write that here I've seen that written 2^2 before However, I'm not sure how readable that would be for most. So: w + (w – 12 ÷ 2^2 • 3) • 7 where w=10 w + (w-12 ÷ 4 * 3) *7 w+ (w- 3 * 3) * 7 w + (w-9) * 7 10 + (10-9) * 7 10 + 1 * 7 10 + 7 17 Multiplication an division are at the same level of order of operations, you do them L to R otherwise Similarly, addition and subtraction are at the same level. Edited September 12, 2012 by vonfirmath Quote Link to comment Share on other sites More sharing options...
LinRTX Posted September 12, 2012 Share Posted September 12, 2012 Actually you work left to right multiplying and/or dividing (so, they are at the level in the order) Quote Link to comment Share on other sites More sharing options...
wapiti Posted September 12, 2012 Share Posted September 12, 2012 umm... a duh moment 22 should be 2 to the 2nd power. Don't know how to write that here Then yes, the answer is 17. Multiply and divide from left to right, so square the 2, then 12/4, then 3 times 3... Quote Link to comment Share on other sites More sharing options...
Ailaena Posted September 12, 2012 Share Posted September 12, 2012 I heard the collective, "Ooohhhh...:D" :lol::lol: Quote Link to comment Share on other sites More sharing options...
Trresh Posted September 12, 2012 Share Posted September 12, 2012 (edited) I heard the collective, "Ooohhhh...:D" :lol::lol: I kid you not. That's exactly what I said out loud!! :lol: Edited September 12, 2012 by Trresh Quote Link to comment Share on other sites More sharing options...
sgo95 Posted September 12, 2012 Share Posted September 12, 2012 If you multiply first, you get what's on the right side of the equation in the attached picture (the left hand is what you should be calculating): Quote Link to comment Share on other sites More sharing options...
BlueTaelon Posted September 12, 2012 Author Share Posted September 12, 2012 Actually you work left to right multiplying and/or dividing (so, they are at the level in the order)[/QUote] Thank you:) I'm learning along with my dd:) Quote Link to comment Share on other sites More sharing options...
justasque Posted September 12, 2012 Share Posted September 12, 2012 Given w = 10, what is the answer to w + (w – 12 ÷ 22 • 3) • 7 I got 73, the test said its wrong and the answer is 17 this did not C&P correctly, the 22 should be an exponent of 2 to the 2nd power The problem is: w+(w-12 / 2^2 x 3) x 7 w = 10 You need to know Please Excuse (My Dear) (Aunt Sally) or PE(MD)(AS), the order of operations. It means first do whatever is in parenthesis, then exponents, then multiplication/division, then addition/subtraction. In all cases, work left to right. When you're working inside parenthesis, apply PE(MD)(AS) to just that part, then when you've gotten it down to one term with no operations, you start again with PE(MD)(AS) on the whole thing. Substitute in the 10 for w: 10 + (10-12/2^2x3)x7 First, do the parenthesis. Start with PD(MD)(AS) again with what's inside the (). Inside them, there are no parenthesis, so do the exponent: 2^2 = 4, so 10 _ (10-12/4x3) x7 Then multiplication and division, moving left to right: 12/4 = 3, so 10 + (10-3x3) x 7 3 x 3 = 9, so 10 + (10-9) x 7 Then the addition/subtraction: 10-9= 1, so 10 + (1) x 7 You can now remove the (), because there are no more operations inside them: 10 + 1 x 7 Now, start over with PE(MD)(AS): no parenthesis, no exponents, so do the multiplication/division: 1 x 7 = 7, so 10 + 7 And now the adding/subtracting: 10+7 = 17, so the answer is: 17 Quote Link to comment Share on other sites More sharing options...
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