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

helpasap111

BEST RESPONSE WILL GET A MEDAL AND A FAN For the following system, if you isolated y in the first equation to use the Substitution Method, what expression would you substitute into the second equation? 4x − y = 8 2x + 3y = 9 8 − 4x 8 + 4x −8 + 4x −8 − 4x

  • one year ago
  • one year ago

  • This Question is Closed
  1. helpasap111
    Best Response
    You've already chosen the best response.
    Medals 0

    help please

    • one year ago
  2. jiteshmeghwal9
    Best Response
    You've already chosen the best response.
    Medals 0

    4x-y=8 Add y both sides wht do u gt ?

    • one year ago
  3. helpasap111
    Best Response
    You've already chosen the best response.
    Medals 0

    i dont understand

    • one year ago
  4. jiteshmeghwal9
    Best Response
    You've already chosen the best response.
    Medals 0

    Adding y both sides 4x-y+y=8+y 4x=8+y

    • one year ago
  5. jiteshmeghwal9
    Best Response
    You've already chosen the best response.
    Medals 0

    Gt it till right here ?

    • one year ago
  6. helpasap111
    Best Response
    You've already chosen the best response.
    Medals 0

    oh yes

    • one year ago
  7. helpasap111
    Best Response
    You've already chosen the best response.
    Medals 0

    what do i do next

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

    Actually what you are being asked to do is find an expression for y in terms of x, and substitute that into the second equation. So if your two equations are 4x − y = 8 2x + 3y = 9 Then from the first equation we have that -y = 8 - 4x hence y = -8 + 4x or y= 4x - 8 This is the expression you would substitute into the second equation, as in 2x + 3y = 9 thus 2x + 3(4x - 8) = 9 Note the the question is NOT asking you to solve the equations. It is just asking you to find an expression for y from the first of each pair of equations which you would substitute into the second equation.

    • one year ago
  9. helpasap111
    Best Response
    You've already chosen the best response.
    Medals 0

    Oh okay

    • one year ago
  10. helpasap111
    Best Response
    You've already chosen the best response.
    Medals 0

    so it's -8-4x?

    • one year ago
  11. helpasap111
    Best Response
    You've already chosen the best response.
    Medals 0

    hello

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

    No 4x - y = 8 Hence -y = 8 - 4x and thus y = -(8-4x) y = 4x - 8

    • one year ago
  13. helpasap111
    Best Response
    You've already chosen the best response.
    Medals 0

    but what if that isnt one of the choices

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

    But it IS one of the choices.

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

    4x - 8 is equal to exactly one of these expressions: 8 − 4x 8 + 4x −8 + 4x −8 − 4x

    • one year ago
  16. helpasap111
    Best Response
    You've already chosen the best response.
    Medals 0

    which one?

    • one year ago
  17. helpasap111
    Best Response
    You've already chosen the best response.
    Medals 0

    8-4x?

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

    4x - 8 Can it be 8 - 4x, I don't think so, because if it were then 4x - 8 = 8 - 4x = -(4x - 8)

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

    Remember that a + b = b + a. This is called the commutative property of addition. Hence 4x - 8 = -8 + 4x

    • 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.