L20 · Solutions of equations

1. 1.

   Is x = 10 a solution of 8x = 80?

   Answer. yes

   8(10) = 80, which equals 80.

2. 2.

   Is x = 5 a solution of 8x = 32?

   Answer. no

   8(5) = 40, which does not equal 32.

3. 3.

   Is x = 5 a solution of 6x = 18?

   Answer. no

   6(5) = 30, which does not equal 18.

4. 4.

   Is x = 6 a solution of 6x = 24?

   Answer. no

   6(6) = 36, which does not equal 24.

5. 5.

   Is x = 11 a solution of 3x = 33? Write a complete answer — Theo will compare with a partner.

   Answer. yes

   3(11) = 33, which equals 33.

6. 6.

   Is x = 12 a solution of 5x = 45? Write a complete answer — Luis will compare with a partner.

   Answer. no

   5(12) = 60, which does not equal 45.

7. 7.

   Is x = 6 a solution of 3x = 18? Write a complete answer — Priya will compare with a partner.

   Answer. yes

   3(6) = 18, which equals 18.

8. 8.

   Is x = 5 a solution of 2x = 10? Write a complete answer — Priya will compare with a partner.

   Answer. yes

   2(5) = 10, which equals 10.

9. 9.

   Is x = 4 a solution of 4x = 16? Write a complete answer — Nora will compare with a partner.

   Answer. yes

   4(4) = 16, which equals 16.

10. 10.

    Is x = 9 a solution of 8x = 56? Write a complete answer — Jonah will compare with a partner.

    Answer. no

    8(9) = 72, which does not equal 56.

11. 11.

    Think

    Mei tried this problem:
    Is x = 10 a solution of 5x = 35?
    Mei wrote yes. That is not correct. What is the right answer?

    Answer. no

    Mei’s answer yes is off. 5(10) = 50, which does not equal 35.

12. 12.

    Think

    Mei tried this problem:
    Is x = 9 a solution of 4x = 36?
    Mei wrote no. That is not correct. What is the right answer?

    Answer. yes

    Mei’s answer no is off. 4(9) = 36, which equals 36.

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