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anonymous

  • one year ago

s=1/2n(a+K) could someone show me how to do this? im confused because i thought you had to multiply the entire equation by 2 but thats giving me wrong answer

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  1. freckles
    • one year ago
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    There isn't enough information in this question.

  2. anonymous
    • one year ago
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    solving for K

  3. freckles
    • one year ago
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    \[s=\frac{1}{2}n(a+K) ?\] If this is right, yes multiplying 2 as a first step is good. But that still will not isolate K yet. You will still have to perform more steps. Is this what you get when you multiply 2 on both sides? 2s=n(a+K) try isolating (a+k) next by undoing the multiplication by n to it.

  4. anonymous
    • one year ago
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    Yeah I get that part I'm just wondering why I dont multiply a and K by 2 and it ends up being 2s=n(a+K) instead

  5. freckles
    • one year ago
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    are you asking why 2/2=1?

  6. anonymous
    • one year ago
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    |dw:1443585029131:dw|

  7. freckles
    • one year ago
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    but 2/2=1

  8. freckles
    • one year ago
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    why you multiply one side by 4 and the other side by 2?

  9. freckles
    • one year ago
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    |dw:1443585130255:dw|

  10. freckles
    • one year ago
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    |dw:1443585146509:dw|

  11. anonymous
    • one year ago
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    oh i see

  12. anonymous
    • one year ago
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    i dont know i was just under the impression that if you multiply by 2 you have to do that to the entire problem but it ends up being 1 so its just a+K

  13. freckles
    • one year ago
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    well you have n(a+k) on the right hand side but yes you multiply 2 on both sides

  14. freckles
    • one year ago
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    whereas you were multiplying 2 on one side and 4 on the other side

  15. anonymous
    • one year ago
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    i was canceling out the 1/2n and just putting it as n but also multiplying 2*a and 2*k because i thought when clearing fractions you had to multiply the entire equation and not just one part of it i wasnt using 4

  16. freckles
    • one year ago
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    you were though you multiply by 2 and then you multiply by another 2 on the right hand side and 2*2 is 4

  17. freckles
    • one year ago
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    see this is what you get on the right hand side side if you multiply by 4 \[4 \cdot \frac{1}{2} n (a+K) \\ \frac{4}{2}n(a+k) \\ 2n(a+k) \\ n(2a+2k)\] which is what you receive in the end on your right hand side

  18. anonymous
    • one year ago
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    |dw:1443585661985:dw|

  19. anonymous
    • one year ago
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    i was doing it like that

  20. freckles
    • one year ago
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    what happen to your n in the end? and you are still multiplying 2 on left hand side and 4 on the right hand side this incorrect you multiply both sides by the same number \[s=\frac{1}{2}n(a+k) \\ 2 \cdot (s)=2 \cdot (\frac{1}{2}n(a+k)) \\ 2s=(2 \cdot \frac{1}{2})n(a+k) \text{ since multiplication is associative } \\ 2s=(1)n(a+k) \text{ since } \frac{2}{2}=1 \\ 2s=n(a+k) \\ \text{ now try dividing both sides by } n \\ \frac{2s}{n}=a+k\] there is one last step to perform

  21. anonymous
    • one year ago
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    oh it makes sense

  22. anonymous
    • one year ago
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    i was distributing it wrong when its already being canceled out

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