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helpasap111 Group Title

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

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  1. helpasap111 Group Title
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    help please

    • one year ago
  2. jiteshmeghwal9 Group Title
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    4x-y=8 Add y both sides wht do u gt ?

    • one year ago
  3. helpasap111 Group Title
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    i dont understand

    • one year ago
  4. jiteshmeghwal9 Group Title
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    Adding y both sides 4x-y+y=8+y 4x=8+y

    • one year ago
  5. jiteshmeghwal9 Group Title
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    Gt it till right here ?

    • one year ago
  6. helpasap111 Group Title
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    oh yes

    • one year ago
  7. helpasap111 Group Title
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    what do i do next

    • one year ago
  8. JamesJ Group Title
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    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 Group Title
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    Oh okay

    • one year ago
  10. helpasap111 Group Title
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    so it's -8-4x?

    • one year ago
  11. helpasap111 Group Title
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    hello

    • one year ago
  12. JamesJ Group Title
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    No 4x - y = 8 Hence -y = 8 - 4x and thus y = -(8-4x) y = 4x - 8

    • one year ago
  13. helpasap111 Group Title
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    but what if that isnt one of the choices

    • one year ago
  14. JamesJ Group Title
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    But it IS one of the choices.

    • one year ago
  15. JamesJ Group Title
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    4x - 8 is equal to exactly one of these expressions: 8 − 4x 8 + 4x −8 + 4x −8 − 4x

    • one year ago
  16. helpasap111 Group Title
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    which one?

    • one year ago
  17. helpasap111 Group Title
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    8-4x?

    • one year ago
  18. JamesJ Group Title
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    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 Group Title
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    Remember that a + b = b + a. This is called the commutative property of addition. Hence 4x - 8 = -8 + 4x

    • one year ago
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