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anonymous

  • one year ago

What is the value of the following expression when x=3 and y=-2? 4x-y2

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  1. DanJS
    • one year ago
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    can you put those values into the expression

  2. DanJS
    • one year ago
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    just the order of ops thing like last time i think

  3. anonymous
    • one year ago
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    @jim_thompson5910

  4. jim_thompson5910
    • one year ago
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    The expression is this right? \[\Large 4x - y^2\]

  5. anonymous
    • one year ago
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    yes!

  6. jim_thompson5910
    • one year ago
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    to start off, replace every x with 3 (since x = 3) \[\Large 4\color{red}{x} - y^2\] \[\Large 4(\color{red}{3}) - y^2\]

  7. anonymous
    • one year ago
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    Sorry brain fart. and I really don't know how to use this site.

  8. jim_thompson5910
    • one year ago
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    Then replace every y with -2 \[\Large 4(3) - \color{red}{y}^2\] \[\Large 4(3) - (\color{red}{-2})^2\]

  9. jim_thompson5910
    • one year ago
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    at this point, you either use pen/paper to compute or a calculator to compute

  10. anonymous
    • one year ago
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    Well 4*3 equals 64.

  11. jim_thompson5910
    • one year ago
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    4*3 does not equal 64

  12. jim_thompson5910
    • one year ago
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    you might be thinking of \(\Large 4^3\)

  13. anonymous
    • one year ago
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    That's what I meant. How you drew it out before kind of like \[4*4*4\]

  14. anonymous
    • one year ago
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    Something like that lol

  15. jim_thompson5910
    • one year ago
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    well in the case of 4*3, it's simply 4 times 3, which is 12

  16. jim_thompson5910
    • one year ago
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    that's different from 4^3, which is 4 to the third power

  17. anonymous
    • one year ago
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    Oh ok!

  18. jim_thompson5910
    • one year ago
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    btw, 4(3) is another way of saying 4*3

  19. anonymous
    • one year ago
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    Oh ok!:)

  20. anonymous
    • one year ago
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    Talking about the final answer. From my calulations, its positive?

  21. jim_thompson5910
    • one year ago
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    The answer is positive. Yes

  22. anonymous
    • one year ago
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    I stuck between 8 and 16.

  23. jim_thompson5910
    • one year ago
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    what is (-2)^2 equal to?

  24. anonymous
    • one year ago
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    -4? I have a feeling that that's incorrect.

  25. jim_thompson5910
    • one year ago
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    we multiply -2 by itself twice

  26. jim_thompson5910
    • one year ago
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    (-2)^2 = (-2)*(-2) = ??

  27. anonymous
    • one year ago
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    -8?

  28. jim_thompson5910
    • one year ago
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    you were correct about the 4 part, it's just positive and not negative -2 times -2 = +4

  29. jim_thompson5910
    • one year ago
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    negative times negative = positive

  30. anonymous
    • one year ago
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    Oh!!!!!

  31. jim_thompson5910
    • one year ago
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    \[\Large \color{red}{4(3)} - \color{blue}{(-2)^2}\] \[\Large \color{red}{12} - \color{blue}{4}\]

  32. anonymous
    • one year ago
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    8

  33. jim_thompson5910
    • one year ago
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    yep

  34. anonymous
    • one year ago
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    Thats the final answer?

  35. jim_thompson5910
    • one year ago
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    yes it is

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