Solve a quadratic by factoring (zero product property)

Answer Key - Grade 9 Math Worksheet

Circle the best answer, or write your answer on the line.

1. 1.

   Jun solves x² - 3x - 40 = 0 on scrap paper. What is the larger solution?

   8
2. 2.

   Kira solves x² + 4x - 45 = 0 before the bell. What is the smaller solution?

   -9
3. 3.

   Luz's robot factors x² - 13x + 42 = 0 and asks for help with the last step. What is the smaller solution?

   6
4. 4.

   In math club, Milo solves x² + 15x + 56 = 0. What is the larger solution?

   -7
5. 5.

   Pia solves x² + 3x = 54 with a fresh pencil. What is the smaller solution?

   -9
6. 6.

   Ren's robot solves x² = 6x + 27. What is the larger solution?

   9
7. 7.

   Zee's puzzle card says x² = 9x. Which gives every solution?

   • x = 9 or x = -9
   • x = 0 or x = 9
   • x = 0 or x = -9
   • x = 9 only
8. 8.

   Ari solves 5x² + 20x = 0 in pencil. Which gives every solution?

   • x = 0 or x = 4
   • x = 4 or x = -4
   • x = 0 or x = -4
   • x = -4 only
9. 9.

   Bo's robot solves x² - 12x = 0 and does not trust shortcuts. Which gives every solution?

   • x = 0 or x = 12
   • x = 0 or x = -12
   • x = 12 only
   • x = 12 or x = -12
10. 10.

    Esme's math book shows 3x² = 21x. Which gives every solution?

    • x = 7 only
    • x = 7 or x = -7
    • x = 0 or x = -7
    • x = 0 or x = 7