A community for students.

Here's the question you clicked on:

55 members online
  • 0 replying
  • 0 viewing

anonymous

  • one year ago

How would you use the quadratic formula to solve x^2+5x=-2. Using compete sentences.

  • This Question is Open
  1. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    @SolomonZelman

  2. SolomonZelman
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    maybe we can work the prob using math, and you do the sentences part alone?

  3. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Okay

  4. SolomonZelman
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    when the equation is \(\LARGE\color{black}{ \color{blue}{a} x^2+ \color{magenta}{b}x+ \color{red}{c}=0 }\). you use the following formula: \(\normalsize\color{ slate }{\Huge{\bbox[5pt, lightcyan ,border:2px solid black ]{ \LARGE{x=~} \huge{ \frac{-\color{magenta}{b} \pm\sqrt{ \color{magenta}{b} ^2-4 \color{blue}{a} \color{red}{c}}}{2 \color{blue}{a}} }~ }}}\) (to transfer your equation to the needed \(\large \color{black}{ \color{blue}{a} x^2+ \color{magenta}{b}x+ \color{red}{c}=0 }\) form, you have to add 2 to both sides.)

  5. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    So it will be x^2+5+2=0

  6. SolomonZelman
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    what do you get after adding 2 to both sides?

  7. SolomonZelman
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    yes

  8. SolomonZelman
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    \(\LARGE\color{black}{ \color{blue}{a} x^2+ \color{magenta}{b}x+ \color{red}{c}=0 }\) ` ... comparing ... ` \(\LARGE\color{black}{ \color{blue}{1} x^2+ \color{magenta}{5}x+ \color{red}{2}=0 }\)

  9. SolomonZelman
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    Now, please plug in the a b c for me....

  10. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    What do you mean by plug in?

  11. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    I have no clue how to do this. I am just learning it

  12. UsukiDoll
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    she meant let a = 1, b = 5, and c = 2 we will have this equation \[x^2+5x+2=0\]

  13. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Okay and then what do I do from there?

  14. UsukiDoll
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    Well, to solve this faster we need the discriminant \[b^2-4ac\] so let b = 5, a =1, and c =2

  15. SolomonZelman
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    who is she?

  16. UsukiDoll
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    umm I thought that was you?

  17. SolomonZelman
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    well, if you are thinking of me as of a good looking girl, rather than a bad looking girl, then you in a sense did tackle my identity.

  18. UsukiDoll
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    anyway plug in b =5, c =2, and a = 1 into the discriminant formula \[b^2-4ac\] @J_slate23

  19. UsukiDoll
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    as in replace the b with 5, replace the c with 2 and replace the a with 1

  20. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    So 5^2=4(1)(2)?

  21. UsukiDoll
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    yes but replace the = with -

  22. UsukiDoll
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    \[5^2-4(1)(2)\]

  23. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    So 5^2-4(1)(2)?

  24. UsukiDoll
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    mhm so now what's 5^2 and what's 4(1)(2)

  25. SolomonZelman
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    \(\normalsize\color{ slate }{\Huge{\bbox[5pt, lightyellow ,border:2px solid black ]{ \LARGE{x=~} \huge{ \frac{-\color{magenta}{5} \pm\sqrt{ \color{magenta}{5} ^2-4 \color{blue}{(1)} \color{red}{(2)}}}{2 \color{blue}{(1)}} }~ }}}\) and your equation is \(\LARGE\color{black}{ \color{blue}{1} x^2+ \color{magenta}{5}x+ \color{red}{2}=0 }\).

  26. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    25 and 8

  27. UsukiDoll
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    yes so now what's 25-8

  28. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    17

  29. UsukiDoll
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    yes! so for the bottom denominator what is 2(1) ?

  30. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    2

  31. UsukiDoll
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    yes

  32. UsukiDoll
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    so now you have \[\frac{5 +\sqrt{17}}{2}, \frac{5-\sqrt{17}}{2}\] I split the signs up because the latex for the quadratic formula is big and nasty

  33. UsukiDoll
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    OH MAN I forgot the -!

  34. UsukiDoll
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    \[\frac{-5 +\sqrt{17}}{2}, \frac{-5-\sqrt{17}}{2}\]

  35. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Is that the answer? If so that was really easy

  36. UsukiDoll
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    yeah.. I just split the sign in the middle up. the latex for the entire quadratic equation with + and - together was a pain

  37. UsukiDoll
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    and 17 is not a perfect square... so we can't simplify .. not to mention 17 is a prime

  38. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    So the final answer is -5+-sqrt17/2?

  39. UsukiDoll
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    yeah

  40. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Thank you!

  41. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    That is easier then I expected

  42. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Can you check my math for another one? @UskiDoll

  43. UsukiDoll
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    sure

  44. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Solve x^2+4x-12=0 by completing the square. X^2+4x-12=0 Add 12 X^2+4x=12 (X+2)^2-4=12 (x+2)^2=16 (x+2)= 4 or -4 X= 6 or -6 is my answer

  45. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Is that correct @UskiDoll

  46. UsukiDoll
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    \[x^2+4x-12=0 \] \[x^2+4x=12 \] \[4 \times \frac{1}{2} = \frac{4}{2} = 2\] \[2^2 = 4\] \[x^2+4x+4=12+4 \] \[x^2+4x+4=16 \] \[(x+2)^2 = 16 \] square root on both sides \[\sqrt{(x+2)^2} = \sqrt{16}\] \[x+2=4, x+2=-4\] \[x=2, x=-6\]

  47. UsukiDoll
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    x+2 = 4 on your part is wrong. subtract 2 from both sides, but -6 is correct

  48. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Okay. Thank you

  49. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    plug it in -b+_ b2-4ac \[\sqrt{b2-4ac}\] / 4a good luck

  50. UsukiDoll
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    The problem is already done ^_^

  51. Not the answer you are looking for?
    Search for more explanations.

    • Attachments:

Ask your own question

Sign Up
Find more explanations on OpenStudy
Privacy Policy

Your question is ready. Sign up for free to start getting answers.

spraguer (Moderator)
5 → View Detailed Profile

is replying to Can someone tell me what button the professor is hitting...

23

  • Teamwork 19 Teammate
  • Problem Solving 19 Hero
  • You have blocked this person.
  • ✔ You're a fan Checking fan status...

Thanks for being so helpful in mathematics. If you are getting quality help, make sure you spread the word about OpenStudy.

This is the testimonial you wrote.
You haven't written a testimonial for Owlfred.