Solve a quadratic by factoring (zero product property)

Answer Key - Grade 9 Math Worksheet - Building Confidence

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

1. 1.

   Kira solves (x - 3)(x + 8) = 0 in pencil. A product is 0 only when one bracket is 0. What is the negative solution?

   -8
2. 2.

   Luz's robot reads (x - 9)(x + 4) = 0 and lights up. A product is 0 only when one bracket is 0. What is the negative solution?

   -4
3. 3.

   In math club, Milo meets (x - 12)(x + 5) = 0. A product is 0 only when one bracket is 0. What is the negative solution?

   -5
4. 4.

   Noah solves (x + 7)(x - 2) = 0 while the kite string untangles. Which inputs make the output 0?

   • x = -7 and x = 2
   • x = -7 only
   • x = 0
   • x = 7 and x = -2
5. 5.

   Pia's puzzle card says (x - 10)(x - 3) = 0. Which inputs make the output 0?

   • x = 10 and x = 3
   • x = 10 only
   • x = 0
   • x = -10 and x = -3
6. 6.

   Tala's robot solves (x - 1)(x + 13) = 0 and wants a second opinion. Which inputs make the output 0?

   • x = 0
   • x = 1 only
   • x = 1 and x = -13
   • x = -1 and x = 13
7. 7.

   Zee fills in a table for y = x² - 3x - 28. It factors as (x + 4)(x - 7). Which input row has output 0?

   • x = 0
   • x = -7
   • x = 7
   • x = 28
8. 8.

   Ari tests rows of the table for y = x² + 2x - 48. It factors as (x + 8)(x - 6). Which input row has output 0?

   • x = -6
   • x = 48
   • x = 0
   • x = 6
9. 9.

   Bo's robot builds a table for y = x² - 11x + 24. It factors as (x - 3)(x - 8). Which input row has output 0?

   • x = 24
   • x = 0
   • x = 8
   • x = -8
10. 10.

    In math club, Esme checks rows of the table for y = x² + 9x + 18. It factors as (x + 6)(x + 3). Which input row has output 0?

    • x = 6
    • x = 18
    • x = -6
    • x = 0