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)
   1	2	8
   2	5	8
   3	9	8
   4	14	8

6. 5.

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

   • At x = 3
   • Where the output is 9 in both columns
   • Between x = 2 and x = 3
7. 6.

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

   • Between x = 6 and x = 7
   • At x = 7
   • Where the output is 9
8. 7.

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

   2
9. 8.

   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
10. 9.

    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
11. 10.

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

    2