Find where two functions are equal using a graph or table

Answer Key - Grade 9 Math Worksheet

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

1. Read this first

   Use the table

   x	f(x)	g(x)
   0	10	0
   5	20	15
   10	30	30
   15	40	45
   20	50	60

2. 1.

   Esme compares two buses by riders on board. The table shows f and g. For which input does f(x) = g(x)?

   10
3. 2.

   Jun's cat and dog each follow a line. The graphs of f (cat) and g (dog) are drawn. For which x is f(x) = g(x)?

   2
4. 3.

   Kira's two bells follow lines. The graphs of f and g are drawn. For which x is f(x) = g(x)?

   4
5. 4.

   Luz's two ducks follow lines. The graphs of f and g are drawn. For which x is f(x) = g(x)?

   5
6. 5.

   Milo compares two pencil clubs: f(x) = 2x + 3 and g(x) = 5x − 6. Make a table to find x where f(x) = g(x).

   3
7. 6.

   Noah compares two snack carts: f(x) = 5x − 9 and g(x) = 2x + 6. Make a table to find x where f(x) = g(x).

   5
8. 7.

   Pia compares two campsites: f(x) = 4x − 3 and g(x) = 2x + 9. Make a table to find x where f(x) = g(x).

   6
9. 8.

   Esme graphs two paths of a cloud. The graphs of f and g cross at (3, 7). What is the solution of f(x) = g(x)?

   • (3, 7)
   • x = 7
   • x = 3
10. 9.

    Jun graphs two kites. The graphs of f and g cross at (5, 12). What is the solution of f(x) = g(x)?

    • (5, 12)
    • x = 12
    • x = 5
11. 10.

    Kira graphs two sled runs. The graphs of f and g cross at (2, 9). What is the solution of f(x) = g(x)?

    • (2, 9)
    • x = 9
    • x = 2