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anonymous

  • one year ago

Solve the system y = -x + 7 and y = -0.5(x - 3)^2 + 8. With an explanation would be good! :)

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  1. cliffordtapp
    • one year ago
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    what is x

  2. dakid88
    • one year ago
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    x means that and do not represent the same math object (Both symbols do not have the same value). (The forms !=, /= or <> are generally used in programming languages where ease of typing and use of ASCII text is preferred.) x ≈ y means x is approximately equal to y.

  3. anonymous
    • one year ago
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    So, how would I solve this? Would i substitute y=-x+7 into the second equation?

  4. jacobciezki
    • one year ago
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    yes

  5. triciaal
    • one year ago
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    yes do the substitution and solve for x

  6. triciaal
    • one year ago
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    with the calculated value for x then put in either original to find y

  7. triciaal
    • one year ago
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    solving the system means you are finding the (x, y) set that satisfies both equation

  8. dakid88
    • one year ago
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    yes

  9. anonymous
    • one year ago
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    Okay. I ended up with y=-0.5({-x+7}-3)^2+8. Is that correct?

  10. dakid88
    • one year ago
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    yes tht is correct

  11. triciaal
    • one year ago
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    |dw:1441813046839:dw|

  12. triciaal
    • one year ago
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    @dakid88 no that is not correct

  13. dakid88
    • one year ago
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    |dw:1441813181344:dw|

  14. triciaal
    • one year ago
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    @Dancingnerd can you continue?

  15. anonymous
    • one year ago
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    Um. I think so. Then, do i just solve from here?

  16. anonymous
    • one year ago
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    I ended up with x = -0.5x^2.. It doesn't seem right.

  17. triciaal
    • one year ago
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    @Dancingnerd do you understand why your expression was wrong?

  18. anonymous
    • one year ago
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    Oh. It should be x = 0.5x^2.

  19. anonymous
    • one year ago
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    Yes.

  20. triciaal
    • one year ago
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    really? how will that give you the value for x ? did you compute that fast?

  21. anonymous
    • one year ago
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    What do you mean? I think I confused myself.

  22. triciaal
    • one year ago
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    what equation did you use?

  23. anonymous
    • one year ago
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    I used -x+7=-0.5(x-3)^2+8.

  24. triciaal
    • one year ago
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    correct equation

  25. anonymous
    • one year ago
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    Okay, so how do I solve?

  26. triciaal
    • one year ago
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    start with the right hand side expand the "exponents" then parenthesis

  27. triciaal
    • one year ago
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    simplify you will get a quadratic to factor

  28. anonymous
    • one year ago
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    -x+7=-0.5*x^2+9+8

  29. triciaal
    • one year ago
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    I have x = 7, x = 1 then find the corresponding values for y

  30. anonymous
    • one year ago
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    (7, 0) and (-1,6) are the points. Is that correct?

  31. triciaal
    • one year ago
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    no I have x = 1

  32. anonymous
    • one year ago
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    That's what I meant. That was the answer that I got.

  33. triciaal
    • one year ago
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  34. anonymous
    • one year ago
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    Thank you so much! I would have never been able to solve that myself.

  35. triciaal
    • one year ago
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    any questions ?

  36. anonymous
    • one year ago
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    I'm still a bit unsure how you got x=7 and x = 1.

  37. triciaal
    • one year ago
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    do you follow the directions starting with the right hand side after setting the y's equal? simplify to the quadratic I used x^2 - 8 x + 7 = 0

  38. triciaal
    • one year ago
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    *did

  39. anonymous
    • one year ago
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    Ah. Okay.

  40. anonymous
    • one year ago
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    I think that was where I messed up.

  41. triciaal
    • one year ago
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    do you understand the process? will you be able to do one by yourself now?

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