Write an equation for a story

Answer Key - Grade 7 Math Worksheet - Challenge Me

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

1. 1.

   Esme watches a whale at -30 m rise 2.5 m each second. After s seconds, the whale is at -5 m. Let s be the number of seconds. What equation matches the story?

   2.5s − 30 = -5
2. 2.

   Kira stirs 1/2 cup of milk into each batch of soup, plus 3/4 cup of broth once. The pot holds 9/4 cups. Let y be the number of batches. What equation matches the story?

   y/2 + 3/4 = 9/4
3. 3.

   Each level, Luz wins x points and loses 2 points to puddles. After 5 levels, Luz has 35 points. Let x be the points won in one level. What equation matches the story?

   5(x − 2) = 35
4. 4.

   Each of 3 backpacks held x books, but Noah took 2 out of each. 21 books are left in all. Let x be the number of books in one backpack. What equation matches the story?

   3(x − 2) = 21
5. 5.

   Each level, Ren wins x points and loses 3 points to puddles. After 4 levels, Ren has 28 points. Let x be the points won in one level. Which equation fits?

   • 4(x + 3) = 28
   • 4(x − 3) = 28
   • 3(x − 4) = 28
   • 4x − 3 = 28
6. 6.

   Tala adds 4 shells to each of 3 buckets. Each bucket held x shells, and now there are 33 shells in all. Let x be the number of shells in one bucket. Which equation fits?

   • 3x + 4 = 33
   • 4(x + 3) = 33
   • 3(x − 4) = 33
   • 3(x + 4) = 33
7. 7.

   Zee is given 3(x − 4) = 15, where x is the points won in one level. Which story matches that equation?

   • Zee wins x points in each of 3 levels, then loses 4 points in one big puddle. Zee has 15 points.
   • Each level, Zee wins x points and loses 4 points to puddles. After 3 levels, Zee has 15 points.
   • Each level, Zee wins x points and loses 3 points to puddles. After 4 levels, Zee has 15 points.
   • Each level, Zee wins x points and a 4-point bonus. After 3 levels, Zee has 15 points.
8. 8.

   Ari is given 5(x + 3) = 55, where x is the number of crayons in one bag. Which story matches that equation?

   • Each of Ari's 3 bags holds x crayons and 5 stickers. There are 55 crayons and stickers in all.
   • Each of Ari's 5 bags holds x crayons, but 3 break in each bag. 55 whole crayons are left in all.
   • Ari has 5 bags with x crayons in each, and 3 loose stickers. There are 55 crayons and stickers in all.
   • Each of Ari's 5 bags holds x crayons and 3 stickers. There are 55 crayons and stickers in all.
9. 9.

   Esme writes 5(x − 2) = 35, where x is the points won in one level. Each level also loses 2 points to puddles. What does (x − 2) stand for?

   • the points kept in all 5 levels
   • the number of levels
   • the points lost in one level
   • the points kept in one level
10. 10.

    Kira writes 3(x − 2) = 21, where x is the books in one backpack. Kira took 2 books out of each of 3 backpacks. What does 3(x − 2) stand for?

    • the books left in all 3 backpacks
    • the number of backpacks
    • the books taken out
    • the books left in one backpack