A community for students.

Here's the question you clicked on:

55 members online
  • 0 replying
  • 0 viewing

anonymous

  • 5 years ago

Use the quadratic formula to find the zeros of the function. y = 16x2 + 40x + 25 A. {-1.25, 1.25} B. {-1.25} C. {-4, 5} D. {-0.8}

  • This Question is Closed
  1. anonymous
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Quadratic formula \[(-b \pm \sqrt{b^2-4ac})/2a\] where a, b, c \[ax^2+bx+c=0\]

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

    Can you see why you need to use the quadratic formula now?

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

    ok Go on the steps to solve it confuse me cuz there so long.

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

    so in your case, 16=a, 40=b, 25=c. Plug them into the equation that Romero showed you.

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

    You want to find the zeros of function Y right? that means y=0 first do that you get \[16x^2+40x+25=0\]

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

    mkay wow go on that makes so much more sense than anything my teachers are saying does

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

    like jessie said a =16 b=40 c=25 now plug them in the equation I gave you on top.

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

    ok then i will then what do i do u dont have to give me the answer i just need the simple non confusing steps ur giving me.... ^^

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

    The \[\pm\]means that you have to do one with + and one with - so it makes sense that you should get two values. You should be able to plug them in and whatever you get is the answer for X

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

    ok ill plug them in for you but you work it out

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

    ok i will i dont need the answer! lol just the steps!

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

    a= 16 b=40 c=25 \[x= (-b \pm \sqrt{b^2-4ac})/2a\] so if I plug them in I get \[x= (-40 + \sqrt{40^2-4*16*25})/(2*16)\] \[x= (-40 - \sqrt{40^2-4*16*25}) / (2*16) \]

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

    so just do all the multiplication division etc and you should get your answers

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

    OH!!!! Ok thank you thank you!! xD

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

    I plugged the first numbers in and then i got 8.75 as my answer... but thats not on the options!

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

    check your signs!!

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

    i did!! thats why it took so long!

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

    Ignore the rest, and look under the radical. Start 40^2, which is 1600. Then look at the rest of what is under the radical. Do -4x16x25. Do you get -1600? So the square root of 1600-1600 is 0.

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

    Are we good to there?

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

    yea i got that

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

    but i didnt get the 1600 part for the first part i accidentally

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

    put 4 because i squared the 40 then wasnt thinking and then i got the square root which was.. 40

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

    so then would you do -40 + 32 ?

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

    wait no im confused

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

    Well remember, 2x16 is 32, but your not adding, you are dividing.

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

    So You would have -40 plus the square root of all that junk that turned out to be zero.

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

    -40/32 is -1.25

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

    ohhhhh so u dont add?

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

    wow ok thx i didnt even see that!!!

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

    No. At the end, you set your equation OVER 2a. In other words, divide it by 2a.

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

    ohhhhh ok?

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

    http://www.regentsprep.org/Regents/math/algtrig/ATE3/quadsongs.htm memorize the equation, if you're in Algerbra or Algerbra 2 you're gonna use it again!

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

    algebra*

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

    ok thx!!! ya im in Algebra IIthe only reason im bad is because of all the confusing steps!!!! :P but thx u helped me ALOT!!!

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

    No problem.

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

    What a pun

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

    wait wait so i wrote the problem down like this: x = (-b + - Square root of… B^2 – 4ac /2a

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

    and then were we doing b^2 - 4ac or somethin?

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

    bc i didnt understand why i would divide by 2a again which was 32

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

    wait ok im confused UGH! i thought i got it!!!

  41. 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.