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

Answer Key - Grade 8 Math Worksheet - Challenge Me

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

1. 1.

   Jun meets the rule y = 4(x − 3) in math club. What is the y-intercept of its line?

   -12
2. 2.

   Kira meets the rule 2y = 8x + 6 in math club. What is the slope of its line?

   4
3. 3.

   Luz meets the rule 3y = 6x − 12 in math club. What is the y-intercept of its line?

   -4
4. 4.

   Ren meets the line y = 3x ÷ 4 − 6 in math club. What is its slope?

   3/4
5. 5.

   Tala meets the line y = -2x ÷ 5 + 1 in math club. What is its slope?

   -2/5
6. 6.

   Ari meets the line y = -x ÷ 2 − 9 in math club. What is its y-intercept?

   -9
7. 7.

   Bo graphs y = 2x + 1 and then y = 2x + 6. How does the new line compare with the first one?

   • Same steepness, moved up 6
   • Same steepness, moved down 5
   • Steeper, through the same point on the y-axis
   • Same steepness, moved up 5
8. 8.

   Jun graphs y = 4x − 2 and then y = 4x + 5. How does the new line compare with the first one?

   • Same steepness, moved up 7
   • Steeper, through the same point on the y-axis
   • Same steepness, moved up 5
   • Same steepness, moved down 7
9. 9.

   After sunset, the temperature at Pia's campsite follows T = -2h + 6, with T in °C after h hours. What does the 6 tell?

   • It will be 6 °C in 2 hours
   • It was 6 °C at sunset (hour 0)
   • The temperature drops 6 °C each hour
10. 10.

    Luz meets the line y = 0.25x − 3.5 in math club. What is its y-intercept?

    -3.5