Read the slope and y-intercept from y = mx + b

Answer Key - Grade 8 Math Worksheet

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

1. 1.

   In math club, Bo meets the line y = -2x − 7. What is its slope?

   -2
2. 2.

   In math club, Kira meets the line y = -5x − 1. What is its y-intercept?

   -1
3. 3.

   In math club, Luz meets the line y = 9x. What is its y-intercept?

   0
4. 4.

   In math club, Milo meets the line y = -3x + 12. What is its y-intercept?

   12
5. 5.

   Noah graphs y = 4x + 6. At what point does the line cross the y-axis? Write it as (x, y).

   (0, 6)
6. 6.

   Pia graphs y = -2x − 3. At what point does the line cross the y-axis? Write it as (x, y).

   (0, -3)
7. 7.

   Ren graphs y = x − 7. At what point does the line cross the y-axis? Write it as (x, y).

   (0, -7)
8. 8.

   Zee sketches the line for y = 3x − 4. Which description matches its graph?

   • Crosses the y-axis at -4 and goes up 3 for each 1 across
   • Crosses the y-axis at 4 and goes up 3 for each 1 across
   • Crosses the y-axis at 3 and goes down 4 for each 1 across
9. 9.

   Luz's bath drains following L = 40 − 8m, with L the liters left after m minutes. What does the -8 in the rule tell you?

   • The bath starts with 8 liters
   • The bath takes 8 minutes to drain
   • The bath gains 8 liters each minute
   • The bath loses 8 liters each minute
10. 10.

    Milo's class fund follows d = 3w + 20, with d the dollars after w weeks. What does the 3 tell?

    • The fund has $3 now
    • The fund started with $3
    • The fund grows by $3 each week