Write an equation for a story

Answer Key - Grade 7 Math Worksheet

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

1. 1.

   Tala's bathtub holds 40 gallons and drains 4 gallons each minute. After x minutes, it holds 16 gallons. Let x be the number of minutes. What equation matches the story?

   40 − 4x = 16
2. 2.

   Ari's sunflower seedling is 4.5 cm tall and grows 1.5 cm each day. After d days, it is 12 cm tall. Let d be the number of days. What equation matches the story?

   1.5d + 4.5 = 12
3. 3.

   Bo has $7.50 and saves $2.25 each week for a telescope. After w weeks, Bo has $18.75. Let w be the number of weeks. What equation matches the story?

   2.25w + 7.5 = 18.75
4. 4.

   Each of Kira's 3 baskets holds x apples and 5 pears. There are 36 fruits in all. Let x be the number of apples in one basket. What equation matches the story?

   3(x + 5) = 36
5. 5.

   Milo has 6 bags with x crayons in each, and 3 loose stickers. There are 39 crayons and stickers in all. Let x be the number of crayons in one bag. Which equation fits?

   • 6x − 3 = 39
   • 3x + 6 = 39
   • 6x + 3 = 39
   • 6(x + 3) = 39
6. 6.

   Noah has 5 boxes with x pencils in each, and 8 loose erasers. There are 53 pencils and erasers in all. Let x be the number of pencils in one box. Which equation fits?

   • 5x + 53 = 8
   • 5x − 8 = 53
   • 5(x + 8) = 53
   • 5x + 8 = 53
7. 7.

   Pia is given 45 − 5x = 20, where x is the number of minutes. Which story matches that equation?

   • Pia's bathtub holds 45 gallons and drains 1 gallon each minute. After x minutes, it holds 20 gallons.
   • Pia's bathtub holds 45 gallons and drains 5 gallons each minute. After x minutes, it holds 20 gallons.
   • Pia's bathtub holds 45 gallons and fills 5 more gallons each minute. After x minutes, it holds 20 gallons.
8. 8.

   Tala is given 6(x + 4) = 60, where x is the number of pencils in one box. Which story matches that equation?

   • Each of Tala's 6 boxes holds x pencils and 4 erasers. There are 60 pencils and erasers in all.
   • Each of Tala's 6 boxes holds x pencils, but 4 are lent out from each box. 60 pencils are left in all.
   • Tala has 6 boxes with x pencils in each, and 4 loose erasers. There are 60 pencils and erasers in all.
   • Each of Tala's 4 boxes holds x pencils and 6 erasers. There are 60 pencils and erasers in all.
9. 9.

   Zee writes 6d + 9 = 45, where d is the number of days. Zee finds 6 shells each day and had some shells at the start. What does the 9 stand for?

   • the number of days
   • the shells Zee starts with
   • the shells at the end
   • the shells found each day
10. 10.

    Ari writes 4(x + 3) = 40, where x is the pencils in one box. Each box also holds 3 erasers. What does (x + 3) stand for?

    • the erasers in one box
    • the number of boxes
    • the pencils and erasers in one box
    • the pencils and erasers in all 4 boxes