Quantcast

Got Homework?

Connect with other students for help. It's a free community.

  • across
    MIT Grad Student
    Online now
  • laura*
    Helped 1,000 students
    Online now
  • Hero
    College Math Guru
    Online now

Here's the question you clicked on:

55 members online
  • 0 replying
  • 0 viewing

lildancngurl Group Title

No matter how hard I try I can not figure out how to factor this: 4a^2-32a+63. Any help please? Thanks so much. Please explain the steps!

  • 2 years ago
  • 2 years ago

  • This Question is Closed
  1. znimon Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    (2 a-9) (2 a-7)

    • 2 years ago
  2. znimon Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    So take the coefficient on the a squared term and multiply that to 63 you need to find two number (we will call them A and B) such that A * B = 4 * 63 and A + B = -32

    • 2 years ago
  3. znimon Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    you do this with other polynomials but the coefficient on the squared term is usually a 1so most people don't teach it that way.

    • 2 years ago
  4. lildancngurl Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    You are fabulous. Thank you so much! No matter how hard I tried, I could not understand it. You've made it so much simpler!

    • 2 years ago
  5. znimon Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    Your welcome.

    • 2 years ago
  6. lildancngurl Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    I do have one more question...The two numbers I got were 14 and 18.. How did you get 7 and 9 from that?

    • 2 years ago
  7. precal Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    znimon is busy at the moment, have you tried to do factor by grouping

    • 2 years ago
  8. precal Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    |dw:1346462806136:dw|

    • 2 years ago
  9. precal Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    |dw:1346462837874:dw|

    • 2 years ago
  10. precal Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    |dw:1346462861944:dw|

    • 2 years ago
  11. precal Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    |dw:1346462941803:dw|

    • 2 years ago
  12. precal Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    |dw:1346462966127:dw|

    • 2 years ago
  13. precal Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    hope that helps

    • 2 years ago
  14. jim_thompson5910 Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    Alternatively, you can set the expression equal to zero to get \[\Large 4a^2-32a+63 = 0\] Now solve for 'a' using the quadratic formula \[\Large a = \frac{-B\pm\sqrt{B^2-4AC}}{2A}\] \[\Large a = \frac{-(-32)\pm\sqrt{(-32)^2-4(4)(63)}}{2(4)}\] \[\Large a = \frac{32\pm\sqrt{1024-1008}}{8}\] \[\Large a = \frac{32\pm\sqrt{16}}{8}\] \[\Large a = \frac{32+\sqrt{16}}{8} \ \text{or} \ a = \frac{32-\sqrt{16}}{8}\] \[\Large a = \frac{32+4}{8} \ \text{or} \ a = \frac{32-4}{8}\] \[\Large a = \frac{36}{8} \ \text{or} \ a = \frac{28}{8}\] \[\Large a = \frac{9}{2} \ \text{or} \ a = \frac{7}{2}\] Now rearrange to get the right sides equal to zero \[\Large a = \frac{9}{2} \ \text{or} \ a = \frac{7}{2}\] \[\Large 2a = 9 \ \text{or} \ 2a = 7\] \[\Large 2a - 9 = 0 \ \text{or} \ 2a - 7 = 0\] Finally, use the zero product property to get \[\Large (2a - 9)(2a - 7) = 0\] So this shows us that \[\Large 4a^2-32a+63 = 0\] factors to \[\Large (2a - 9)(2a - 7)\]

    • 2 years ago
  15. lildancngurl Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    Wow, extraordinarily helpful. Thank you!

    • 2 years ago
  16. precal Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    yw

    • 2 years ago
    • Attachments:

See more questions >>>

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.