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

Answer Key - Grade 8 Math Worksheet - Building Confidence

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

1. 1.

   In math club, Ari fills a table for y = 3x + 5: 0 | 5; 1 | 8; 2 | 11. What is the y-intercept of the line?

   5
2. 2.

   In math club, Esme fills a table for y = 4x − 1: 0 | -1; 1 | 3; 2 | 7. What is the y-intercept of the line?

   -1
3. 3.

   Jun copies the rule y = 5x + 9 from the board. What is the slope of its line?

   5
4. 4.

   Kira copies the rule y = x + 6 from the board. What is the slope of its line?

   1
5. 5.

   Luz copies the rule y = -4x + 3 from the board. What is the slope of its line?

   -4
6. 6.

   Noah copies the rule y = 6x − 2 from the board. What is the y-intercept of its line?

   -2
7. 7.

   Pia copies the rule y = 7x + 4 from the board. What is the y-intercept of its line?

   4
8. 8.

   Ren copies the rule y = 2x − 5 from the board. What is the y-intercept of its line?

   -5
9. 9.

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

   • Crosses the y-axis at -3 and goes up 4 for each 1 across
   • Crosses the y-axis at 4 and goes down 3 for each 1 across
   • Crosses the y-axis at 4 and goes up 3 for each 1 across
10. 10.

    Ari sketches the line for y = x + 3. Which description matches its graph?

    • Crosses the y-axis at 3 and stays flat
    • Crosses the y-axis at 3 and goes up 1 for each 1 across
    • Crosses the y-axis at 1 and goes up 3 for each 1 across