Find where two functions are equal using a graph or table

Answer Key - Grade 9 Math Worksheet - Challenge Me

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

1. 1.

   Tala compares two plants: f(x) = 0.5x + 7 and g(x) = 1.5x − 2. Make a table to find x where f(x) = g(x).

   9
2. 2.

   Zee compares two robots: f(x) = 1.5x + 2 and g(x) = 0.5x + 6. Make a table to find x where f(x) = g(x).

   4
3. 3.

   Ari compares two bikes: f(x) = 2.5x − 3 and g(x) = 0.5x + 7. Make a table to find x where f(x) = g(x).

   5
4. 4.

   Bo compares two swings: f(x) = 1.5x − 3 and g(x) = 0.5x + 5. Make a table to find x where f(x) = g(x).

   8

5. Read this first

   Use the table

   x	f(x)	g(x)
   2	6	4
   3	10	8
   4	12	13
   5	13	18

6. 5.

   Luz's two swings are in the table (heights in dm). Where is f(x) = g(x)?

   • At x = 4
   • Where the output is 12 in the table
   • Between x = 3 and x = 4
7. 6.

   Milo's two plants are in the table (heights in cm). Where is f(x) = g(x)?

   • Where the output is 12 in the output column
   • At x = 6
   • Between x = 5 and x = 6
8. 7.

   Noah's two balls are in the table (heights in dm). Where is f(x) = g(x)?

   • Between x = 2 and x = 3
   • At x = 3
   • Where the output is 9 in both columns
9. 8.

   Pia's two robots are in the table (stars). Where is f(x) = g(x)?

   • At x = 7
   • Between x = 6 and x = 7
   • Where the output is 9
10. 9.

    Tala's two bike riders, f and g, are in the table. For how many inputs in the table is f(x) = g(x)?

    0
11. 10.

    Zee's two snack carts, f and g, are in the table. For how many inputs in the table is f(x) = g(x)?

    1