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

burhan101 Group Title

Solve for x

  • one year ago
  • one year ago

  • This Question is Closed
  1. burhan101 Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    \[\huge (5)(8)^{(x+2)} = 5^{7x}\]

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

    \[5 \dot\ 8^{x+2} = 5^{7x} \\ 5 \dot\ 8^x 8^2 = \left(5{^7}\right)^x \\5 \dot\ 8^2 = \frac{\left(5{^7}\right)^x}{8^x} \\5 \dot\ 64 = \left(\frac{5^7}{8}\right)^x \\320 = \left(\frac{5^7}{8}\right)^x \] Take logs of both sides and finish simplifying

    • one year ago
  3. burhan101 Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    |dw:1359086666173:dw|

    • one year ago
  4. burhan101 Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    this is what i'm getting, but it is wrong

    • one year ago
  5. burhan101 Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    wait, we're we sipposed to take the log of both sides?

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

    \[\ln(320) = \ln\left(\left(\frac{5^7}{8}\right)^x\right) \\\ln(320) = x \ln\left(\frac{5^7}{8}\right) \\\frac{\ln(320)}{\ln\left(\frac{5^7}{8}\right)} = x \\\frac{\ln(320)}{\ln5^7 - \ln2^3} = x \\\frac{\ln(320)}{7\ln5 - 3\ln2} = x\]

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

    Uh, ya....logs of both sides. What you do to one side, you do to the other side.

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

    The last two lines, either form, is what you want.

    • one year ago
  9. burhan101 Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    okay thanks !

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

    By the way, don't forget that you are isolating x bro. Don't confuse the numerator and the denominator.

    • one year ago
  11. burhan101 Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    yeah i know but im getting a weird answer idk why -.-

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

    You should have gotten what I got above. And if you're approximating, you should get x ≈ 0.628

    • one year ago
  13. burhan101 Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    • one year ago
    1 Attachment
  14. Hero Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    You did not isolate x properly bro.

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

    Take a look at your second to last step.

    • one year ago
  16. burhan101 Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    ohhh, i figured it. i flipped it

    • one year ago
  17. burhan101 Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    got it ! thanks man :)

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

    Wow....bro

    • one year 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.