A community for students.

Here's the question you clicked on:

55 members online
  • 0 replying
  • 0 viewing

anonymous

  • one year ago

Solve the following system of equations y = −x2 + 4 y = 2x + 1 Can someone help me with this one? I got no answer but I think it's wrong

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

    -x^2 + 4 = 2x + 1 -x^2 - 2x + 3 = 0 factor

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

    would it be x = 1 or x = -3 ?

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

    Do you mean there are two equations \(\sf y = −x2 + 4~and~y = 2x + 1\) ?

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

    yeah

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

    You can subtract second equation from first one to get a quadratic equation in terms of x only and then solve it to find the value of x. Finally substitute this value of x in any of the parent equation to find the value of y

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

    So -x^2 +4 = 2x + 1 and I still get x=1 or -3

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

    |dw:1440863625115:dw|

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

    So that gives you a quadratic equation \(\sf x=\Large \frac{2 \pm \sqrt{2^2-(4 \times-1 \times 3)}}{2}\)

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

    Solve for c:

  10. 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.