Worksheet

Write y = mx + b from a table, graph or story, and say what m and b mean

Grade 8 Math Worksheet - Challenge Me

NameDate

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

  1. Read this first

    Use the table

    input: xoutput: y
    513
    15
    819

  2. Bo's math-club table shows a line, with uneven steps and no row for x = 0. What rule, written as y = mx + b, gives every row?

  3. Jun draws a line on a grid with negative numbers. Points A and B are marked, but neither is on the y-axis. What rule, written as y = mx + b, gives this line?

  4. Luz draws a line on a grid with negative numbers. Points A and B are marked, but neither is on the y-axis. What rule, written as y = mx + b, gives this line?

  5. Water freezes at 32 °F (0 °C) and boils at 212 °F (100 °C). Milo wants a rule for any temperature. What rule gives F from C, as F = mC + b?

  6. Snow in Noah's yard melts steadily: 50 cm deep on day 2, 35 cm on day 7. Let x be days and y cm. What rule gives y, as y = mx + b?

  7. On a steady ride, Pia is 4 km from home at minute 10, 13 km at minute 40. Let x be minutes, y km. What rule gives y, as y = mx + b?

  8. Ren uses F = 1.8C + 32 to change °C into °F. What does the 1.8 tell you?

    • 1.8 °C is the same as 32 °F
    • Water freezes at 1.8 °F
    • Each 1 °C warmer is 1.8 °F warmer

  9. The snow in Tala's yard follows y = -3x + 56, its depth in cm after x days. What does the -3 tell you?

    • The snow was 3 cm deep at day 0
    • The snow has melted completely after 3 days
    • The snow gets 3 cm less deep each day
    • The snow gets 3 cm deeper with each passing day

  10. Esme makes up a story for y = -50x + 600, with x in hours. Which story fits the rule?

    • A bottle holds 650 mL in all
    • A bottle holds 600 mL, and 50 mL is added each hour
    • A bottle holds 600 mL, and 50 mL is drunk each hour
    • A bottle holds 50 mL, and 600 mL is drunk each hour

  11. Jun makes up a story for y = 1.5x + 4, with x in weeks. Which story fits the rule?

    • A seed starts at 0 cm and grows 1.5 cm each week
    • A plant is 1.5 cm tall and grows 4 cm each week
    • A plant is 5.5 cm tall and stops growing
    • A plant is 4 cm tall and grows 1.5 cm each week
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Write y = mx + b from a table, graph or story, and say what m and b mean

Answer Key - Grade 8 Math Worksheet - Challenge Me

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

  1. Read this first

    Use the table

    input: xoutput: y
    513
    15
    819

  2. Bo's math-club table shows a line, with uneven steps and no row for x = 0. What rule, written as y = mx + b, gives every row?

    y = 2x + 3

  3. Jun draws a line on a grid with negative numbers. Points A and B are marked, but neither is on the y-axis. What rule, written as y = mx + b, gives this line?

    y = 3x ÷ 4 + 2

  4. Luz draws a line on a grid with negative numbers. Points A and B are marked, but neither is on the y-axis. What rule, written as y = mx + b, gives this line?

    y = 2x − 9

  5. Water freezes at 32 °F (0 °C) and boils at 212 °F (100 °C). Milo wants a rule for any temperature. What rule gives F from C, as F = mC + b?

    F = 1.8C + 32

  6. Snow in Noah's yard melts steadily: 50 cm deep on day 2, 35 cm on day 7. Let x be days and y cm. What rule gives y, as y = mx + b?

    y = -3x + 56

  7. On a steady ride, Pia is 4 km from home at minute 10, 13 km at minute 40. Let x be minutes, y km. What rule gives y, as y = mx + b?

    y = 3x ÷ 10 + 1

  8. Ren uses F = 1.8C + 32 to change °C into °F. What does the 1.8 tell you?

    • 1.8 °C is the same as 32 °F
    • Water freezes at 1.8 °F
    • Each 1 °C warmer is 1.8 °F warmer

  9. The snow in Tala's yard follows y = -3x + 56, its depth in cm after x days. What does the -3 tell you?

    • The snow was 3 cm deep at day 0
    • The snow has melted completely after 3 days
    • The snow gets 3 cm less deep each day
    • The snow gets 3 cm deeper with each passing day

  10. Esme makes up a story for y = -50x + 600, with x in hours. Which story fits the rule?

    • A bottle holds 650 mL in all
    • A bottle holds 600 mL, and 50 mL is added each hour
    • A bottle holds 600 mL, and 50 mL is drunk each hour
    • A bottle holds 50 mL, and 600 mL is drunk each hour

  11. Jun makes up a story for y = 1.5x + 4, with x in weeks. Which story fits the rule?

    • A seed starts at 0 cm and grows 1.5 cm each week
    • A plant is 1.5 cm tall and grows 4 cm each week
    • A plant is 5.5 cm tall and stops growing
    • A plant is 4 cm tall and grows 1.5 cm each week