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.

   Zee has a jar of 50 beads. Each bracelet uses 6 beads. After s bracelets, 14 beads are left. Let s be the number of bracelets. What equation matches the story?

   50 − 6s = 14
3. 3.

   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
4. 4.

   Each of Esme's 4 boxes holds x pencils and 3 erasers. There are 40 pencils and erasers in all. Let x be the number of pencils in one box. What equation matches the story?

   4(x + 3) = 40
5. 5.

   Each of Jun's 6 bags holds x crayons and 2 stickers. There are 54 crayons and stickers in all. Let x be the number of crayons in one bag. What equation matches the story?

   6(x + 2) = 54
6. 6.

   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
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 fills 5 more gallons 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 drains 1 gallon 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?

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

   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 pencils and erasers in one box
   • the erasers in one box
   • the pencils and erasers in all 4 boxes
   • the number of boxes
10. 10.

    Bo writes 40 − 4x = 16, where x is the number of minutes a 40-gallon tub drains at 4 gallons a minute. What does 4x stand for?

    • the gallons the tub holds
    • the number of minutes
    • the gallons left in the tub
    • the gallons that drained out