Write y = mx + b from a slope and a point, a y-intercept and a point, or two points

Grade 8 Math Worksheet - Challenge Me

NameDate

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

  1. Kira's line passes through (-3, 4) and (3, 0). What rule, written as y = mx + b, gives the line?

  2. Luz's line passes through (-4, -1) and (4, 5). What rule, written as y = mx + b, gives the line?

  3. Milo's line passes through (2, 5.5) and (6, 7.5). What rule, written as y = mx + b, gives the line?

  4. Noah's line passes through (5, 3.5) and (10, 8). What rule, written as y = mx + b, gives the line?

  5. Ren's candle is 30 cm tall at hour 2 and 24 cm at hour 5. Let x be hours and y the height in cm. What rule gives y, as y = mx + b?

  6. Tala's bottle starts at 750 mL and has 600 mL after 3 steady hours of sipping. Let x be hours and y the mL left. What rule gives y, as y = mx + b?

  7. Ari's line passes through (2, 7) and (4, 3). What is y on the line when x = 5?

  8. Bo's line passes through (-1, 1) and (2, 7). What is y on the line when x = 5?

  9. Jun wants a rule for the line through (1, 9) and (4, 3). Which rule fits both points?

    • y = 2x + 11
    • y = -2x + 9
    • y = 11x − 2
    • y = -2x + 11
  10. Kira wants a rule for the line through (2, 1) and (6, 7). Which rule fits both points?

    • y = 2x ÷ 3 − 2
    • y = 3x ÷ 2 + 2
    • y = 3x ÷ 2 + 1
    • y = 3x ÷ 2 − 2
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Write y = mx + b from a slope and a point, a y-intercept and a point, or two points

Answer Key - Grade 8 Math Worksheet - Challenge Me

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

  1. Kira's line passes through (-3, 4) and (3, 0). What rule, written as y = mx + b, gives the line?

    y = -2x ÷ 3 + 2
  2. Luz's line passes through (-4, -1) and (4, 5). What rule, written as y = mx + b, gives the line?

    y = 3x ÷ 4 + 2
  3. Milo's line passes through (2, 5.5) and (6, 7.5). What rule, written as y = mx + b, gives the line?

    y = 0.5x + 4.5
  4. Noah's line passes through (5, 3.5) and (10, 8). What rule, written as y = mx + b, gives the line?

    y = 0.9x − 1
  5. Ren's candle is 30 cm tall at hour 2 and 24 cm at hour 5. Let x be hours and y the height in cm. What rule gives y, as y = mx + b?

    y = -2x + 34
  6. Tala's bottle starts at 750 mL and has 600 mL after 3 steady hours of sipping. Let x be hours and y the mL left. What rule gives y, as y = mx + b?

    y = -50x + 750
  7. Ari's line passes through (2, 7) and (4, 3). What is y on the line when x = 5?

    1
  8. Bo's line passes through (-1, 1) and (2, 7). What is y on the line when x = 5?

    13
  9. Jun wants a rule for the line through (1, 9) and (4, 3). Which rule fits both points?

    • y = 2x + 11
    • y = -2x + 9
    • y = 11x − 2
    • y = -2x + 11
  10. Kira wants a rule for the line through (2, 1) and (6, 7). Which rule fits both points?

    • y = 2x ÷ 3 − 2
    • y = 3x ÷ 2 + 2
    • y = 3x ÷ 2 + 1
    • y = 3x ÷ 2 − 2