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anonymous

  • one year ago

Can someone help me with substitution? Anyone?

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  1. sepeario
    • one year ago
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    No problems.

  2. pooja195
    • one year ago
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    Hi there! Welcome to Openstudy! :D Please post your question so that we can assist u :)

  3. anonymous
    • one year ago
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    Y=5x-7 Y=3/2x+6

  4. sepeario
    • one year ago
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    Okay if you have that and we know that obviously y=y then we can also show that 5x-7=3/2x+6, correct?

  5. sepeario
    • one year ago
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    Okay if you have that and we know that obviously y=y then we can also show that 5x-7=3/2x+6, correct? \[5x-7=\frac{ 3 }{ 2x }+6\]

  6. sepeario
    • one year ago
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    Can you then solve for x?

  7. pooja195
    • one year ago
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    Ok well when we use the susbtistuion mthod we basically substitue a given value into one of the equations lets call Equation A - Y=5x-7 Equation B-Y=3/2x+6 Y value is given you can sub either equation into each other for now lets sub equation A into equation B \[\huge~\rm~5x-7=3/2x+6\]

  8. pooja195
    • one year ago
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    Now all you do is solve for x if you need help with that ill be glad to help ^_^

  9. anonymous
    • one year ago
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    How would I solve for x though? First I know I could add 7 to both sides making the equation 5x=3/2x+13 but then idk how to cancel the x's

  10. pooja195
    • one year ago
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    well subtract the x's from both side :) 5x-3/2x=?

  11. anonymous
    • one year ago
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    But wait XD the x is connected to the 3/2 fraction. You can't subtract it 😭

  12. pooja195
    • one year ago
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    ignore the x's for now

  13. sepeario
    • one year ago
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    lol k

  14. pooja195
    • one year ago
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    5-3/2=?

  15. anonymous
    • one year ago
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    Hmmm but then 3/2 is still a fraction tho O:

  16. pooja195
    • one year ago
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    You can subtract fraction :o did u know that?? :D

  17. anonymous
    • one year ago
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    Hmmm but then 3/2 is still a fraction tho O:

  18. pooja195
    • one year ago
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    o.O

  19. anonymous
    • one year ago
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    LOL MY BAD. would it be like 5/1 - 3/2?

  20. anonymous
    • one year ago
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    LOL MY BAD. would it be like 5/1 - 3/2?

  21. pooja195
    • one year ago
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    ok let me just explain this one to u Ok well when we use the substitution method we basically substitute a given value into one of the equations lets call Equation A - Y=5x-7 Equation B-Y=3/2x+6 Y value is given you can sub either equation into each other for now lets sub equation A into equation B \[\huge~\rm~5x-7=3/2x+6\] We add 7 to both sides \(\huge\color{red}{5x=3/2x+13}\) Then we subtract x's from both sides For x we get 26/7 Then we substitute the value of x into Equation A \[\huge~\rm~5(26/7)-7\] Once you simplify you get y=81/7

  22. pooja195
    • one year ago
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    (26/7,81/7)

  23. anonymous
    • one year ago
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    How did you get 26/7 (sorry I just really don't understand) 😭😭😭😭

  24. mathstudent55
    • one year ago
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    \(y=5x-7\) \( y=\dfrac{3}{2}x+6\) Since y = y, we can set the right sides equal to each other and solve for x. \(5x - 7 = \dfrac{3}{2}x + 6\) \(5x - \dfrac{3}{2}x + 13\) \(\dfrac{10}{2}x - \dfrac{3}{2}x = 13\) \(\dfrac{7}{2} x = 13\) \(x = \dfrac{26}{7}\) Now that we know what x is, we plug in the value we have for x into the first original equation to find y. \(y = 5(\dfrac{26}{7}) - 7\) \(y = \dfrac{130}{7} - \dfrac{49}{7} \) \(y = \dfrac{81}{7} \)

  25. pooja195
    • one year ago
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    Thats what i did

  26. mathstudent55
    • one year ago
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    @Pooja195 You wrote: "We add 7 to both sides 5x=3/2x+13 Then we subtract x's from both sides For x we get 26/7" I'm not as smart as you, so it takes me a few more steps than it took you to find what x was equal to. Since the poster asked how you got 26/7 for x, I thought I'd show the extra steps it took me to find x.

  27. pooja195
    • one year ago
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    Never said i was a smart person. Just didnt realize the difference thanks for explaining.

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