A community for students.

Here's the question you clicked on:

55 members online
  • 0 replying
  • 0 viewing

anonymous

  • one year ago

If (9x − 4)(9x + 4) = ax2 − b, what is the value of a? The value of a is _____________.

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

    @jim_thompson5910

  2. jim_thompson5910
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    hint: (x-y)*(x+y) = x^2 - y^2

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

    i stoll dont get it im lost as to how u solve these

  4. jim_thompson5910
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    has your teacher covered the difference of squares rule in any of the lessons?

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

    im taking an online course so the only explanation for problems we have are written down lessons and it hard for me to learn tht way

  6. jim_thompson5910
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    read this article and tell me if it helps or not http://www.purplemath.com/modules/specfact.htm

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

    ok

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

    not really but if u exokain to me i should pick up quickly

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

    *explain

  10. jim_thompson5910
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    have you learned of the FOIL rule at all?

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

    o ok yes

  12. jim_thompson5910
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    so you will FOIL out (9x-4)*(9x+4)

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

    u multiply the first outside then inner then last

  14. jim_thompson5910
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    yes

  15. jim_thompson5910
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    what do you get when you FOIL ?

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

    well wen i did the first terms i got 81 wich feels wrong to me

  17. jim_thompson5910
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    it's close, it should be 81x^2

  18. jim_thompson5910
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    notice how ax^2 and 81x^2 match up

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

    o ok i know it was x^2 but i was unsure about the 81 part

  20. jim_thompson5910
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    ah ok

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

    my bad my mom called me but b1x^2+36x-36x+16?

  22. jim_thompson5910
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    you mean 81x^2 + 36x - 36x + 16 right?

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

    yes lol my bad

  24. jim_thompson5910
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    what happens with the 36x and the -36x ?

  25. jim_thompson5910
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    they combine to what?

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

    cancell out of the equation leaving u with81x^2+16

  27. jim_thompson5910
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    oh my bad, the +16 should be -16

  28. jim_thompson5910
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    but yes they cancel

  29. jim_thompson5910
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    you should get 81x^2 - 16

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

    o yea becuse its a negative four time positive 4

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

    o ok thenw ats next

  32. jim_thompson5910
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    compare ax^2 - b with 81x^2 - 16

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

    so its 81?

  34. jim_thompson5910
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    a = 81, yes

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

    can u help with more?

  36. jim_thompson5910
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    sure, one more

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

    ok thank you

  38. jim_thompson5910
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    np

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

    Choose the correct simplification of 8x2(4x + 2x2 − 1).

  40. jim_thompson5910
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    when you distributed, what did you get?

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

    WHEN I DISTRIBUTE WAT DO I DO WITH THE ^2 THATS ON THE 8

  42. jim_thompson5910
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    you basically multiply 8x^2 by each term inside

  43. jim_thompson5910
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    |dw:1438821206787:dw|

  44. jim_thompson5910
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    |dw:1438821231018:dw|

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

    FIRST IS 32X^3 THEN 16X^4 THEN -8X^2?

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

    BUT U HAVE TO PUT IT IN STANDARD FORM RIGHT?

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

    ?

  48. jim_thompson5910
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    good |dw:1438821424219:dw|

  49. jim_thompson5910
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    then yeah, write the terms where the largest exponent comes first, then the next largest and so on

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

    OK I GOT THE ANSWER THANK YOU CAN U HELP WITH ONE MORE ITS A QUICK ONE ITS JUST CONFUSING

  51. jim_thompson5910
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    ok

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

    Choose the polynomial written in standard form. xy2 + 4x4y + 10x2 x4y2 + 4x3y + 10x x4y2 + 4x3y5 + 10x2 x6y2 + 4x3y8 + 10x

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

    MY BAD LET ME WRITE THEM CORRECTLY

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

    XY^2+4X^4Y+10X^2 X^4Y^2+4X^3Y+10X X^4Y^2+4X^3Y^5+10X^2 X^6Y^2+4X^3Y^8+10X

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

    I KNOW THEY NEED TO BE IN ORDER BUT NONE OF THEM ARE FROM HIGHEST EXPONENT TO LOWEST

  56. jim_thompson5910
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    whenever you have mixed variables like this, you add the exponents for each term then see if those sums are in descending order

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

    OK SO IS IT B?

  58. jim_thompson5910
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    For example, look at choice D first term is x^6y^2, the sum of the exponents is 6+2 = 8 second term is 4x^3y^8, the sum of the exponents is 3+8 = 11 the sum goes from 8 to 11, which is NOT decreasing, so D is out

  59. jim_thompson5910
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    yes the sums of the exponents for choice B are decreasing

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

    OK THANK YOU SO MUCH MAN

  61. jim_thompson5910
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    np

  62. 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.