Change between Ax + By = C and y = mx + b, and read the slope and intercepts

Answer Key - Grade 9 Math Worksheet - Challenge Me

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

1. 1.

   The line is 6s + 5w = 60. Milo uses 60 minutes on s songs at 6 minutes and w drills at 5 minutes: 6s + 5w = 60. With s across and w up, what is the slope of the line?

   -6/5

2. Read this first

   Use this

   Input–output table of two rows (across | up), the intercept row marked.

3. 2.

   Bo has $40 for s snack packs at $5 and j juices at $2: 5s + 2j = 40. With s across and j up, the y-intercept is (0, 20). What does the 20 tell?

   • 20 juices fit if there are no snack packs
   • Each juice costs $20
   • 20 snack packs fit if there are no juices
4. 3.

   Pia has $40 for s snack packs at $5 and j juices at $2: 5s + 2j = 40. With s across and j up, the x-intercept is (8, 0). What does the 8 tell?

   • 8 juices fit if there are no snack packs
   • 8 snack packs fit if there are no juices
   • Each snack pack costs $8
5. 4.

   Jun plans 36 minutes: w warm-ups at 4 minutes and d drills at 3 minutes, so 4w + 3d = 36. The intercept (0, 12) has w across, d up. What does the 12 tell?

   • 12 drills fit if there are no warm-ups
   • Each drill takes 12 minutes
   • 12 warm-ups fit if there are no drills

6. Input–output table

   x	y
   0	5
   3	3

   Check a row in each choice.

7. 5.

   Tala's rule is y = -2x/3 + 5. Which equation in the form Ax + By = C is the same line?

   • 2x + 3y = 15
   • 2x − 3y = -15
   • 2x + 3y = 5
   • 3x + 2y = -15
8. 6.

   Luz's rule is y = 3x/4 − 1. Which equation in the form Ax + By = C is the same line?

   • 3x + 4y = -4
   • 4x − 3y = 4
   • 3x − 4y = 1
   • 3x − 4y = 4
9. 7.

   Ari's rule is y = -x/2 + 5. Which equation in the form Ax + By = C is the same line?

   • x + 2y = 5
   • 2x + y = -10
   • x − 2y = -10
   • x + 2y = 10
10. 8.

    Noah's rule is y = 5x/2 + 1. Which equation in the form Ax + By = C is the same line?

    • 5x − 2y = -1
    • 5x + 2y = 2
    • 2x − 5y = -2
    • 5x − 2y = -2
11. 9.

    The slope 1.5 is 3/2. Ren's rule is y = 1.5x + 2. What is the same line in the form Ax + By = C, with whole numbers and A positive?

    3x − 2y = -4
12. 10.

    The slope -0.4 is -2/5. Kira's rule is y = -0.4x + 2. What is the same line in the form Ax + By = C, with whole numbers and A positive?

    2x + 5y = 10