L4 · Represent proportional relationships

1. 1.

   A proportional relationship has constant of proportionality 9. Write an equation for y in terms of x.

   Answer. y = 9x

   y = kx with k = 9 gives y = 9x.

2. 2.

   A proportional relationship has constant of proportionality 8. Write an equation for y in terms of x.

   Answer. y = 8x

   y = kx with k = 8 gives y = 8x.

3. 3.

   A proportional relationship has constant of proportionality 2. Write an equation for y in terms of x.

   Answer. y = 2x

   y = kx with k = 2 gives y = 2x.

4. 4.

   A proportional relationship has constant of proportionality 5. Write an equation for y in terms of x.

   Answer. y = 5x

   y = kx with k = 5 gives y = 5x.

5. 5.

   A proportional relationship has constant of proportionality 5. Write an equation for y in terms of x. Write a complete answer — Theo will compare with a partner.

   Answer. y = 5x

   y = kx with k = 5 gives y = 5x.

6. 6.

   A proportional relationship has constant of proportionality 3. Write an equation for y in terms of x. Write a complete answer — Mei will compare with a partner.

   Answer. y = 3x

   y = kx with k = 3 gives y = 3x.

7. 7.

   A proportional relationship has constant of proportionality 6. Write an equation for y in terms of x. Write a complete answer — Priya will compare with a partner.

   Answer. y = 6x

   y = kx with k = 6 gives y = 6x.

8. 8.

   A proportional relationship has constant of proportionality 4. Write an equation for y in terms of x. Write a complete answer — Owen will compare with a partner.

   Answer. y = 4x

   y = kx with k = 4 gives y = 4x.

9. 9.

   A proportional relationship has constant of proportionality 5. Write an equation for y in terms of x. Write a complete answer — Mei will compare with a partner.

   Answer. y = 5x

   y = kx with k = 5 gives y = 5x.

10. 10.

    A proportional relationship has constant of proportionality 7. Write an equation for y in terms of x. Write a complete answer — Mei will compare with a partner.

    Answer. y = 7x

    y = kx with k = 7 gives y = 7x.

11. 11.

    Think

    Mei tried this problem:
    A proportional relationship has constant of proportionality 7. Write an equation for y in terms of x.
    Mei wrote y = -7x. That is not correct. What is the right answer?

    Answer. y = 7x

    Mei’s answer y = -7x is off. y = kx with k = 7 gives y = 7x.

12. 12.

    Think

    Malik tried this problem:
    A proportional relationship has constant of proportionality 3. Write an equation for y in terms of x.
    Malik wrote y = -3x. That is not correct. What is the right answer?

    Answer. y = 3x

    Malik’s answer y = -3x is off. y = kx with k = 3 gives y = 3x.

Original extra practice. Keys are computed from the items, not guessed.