Terms, factors and coefficients, and what each part means in a story

Answer Key - Grade 9 Math Worksheet - Challenge Me

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

1. 1.

   Esme's video has V = 800(1.2)^d views after d days. By what percent do the views grow each day?

   • 20% more each day
   • 1.2 more views each day
   • 120% more each day
   • 1.2% more each day
2. 2.

   Jun's phone charge is B = 100(0.9)^h percent after h hours. By what percent does the charge fall each hour?

   • the charge starts at 0.9 percent
   • 10% less each hour
   • 0.9% less each hour
   • 90% less each hour
3. 3.

   A pond's plant count is N = 200(1.5)^w after w weeks. Kira wants the statement that reads the formula correctly. Which one is right?

   • 200 is the count after w weeks, and 1.5 is the start
   • 200 is the multiplier, and the count starts at 1.5
   • 200 is the start, and each week multiplies the count by 1.5
   • 200 is the start, and each week adds 1.5 plants
4. 4.

   A balance is B = 500(1.04)^t dollars after t years. Luz asks what the 1.04 tells you.

   • the balance grows by $1.04 each year
   • the account starts with $1.04
   • the balance grows by 104% each year
   • each year the balance is 104% of the year before
5. 5.

   A bouncing ball reaches H = 90(1 − r)^n cm on bounce n, with r = 0.1 for each bounce. Pia asks by what factor the height is multiplied after 2 bounces.

   0.81
6. 6.

   Ren's phone charge is B = 100(1 − r)^h percent after h hours, with r = 0.2 each hour. By what factor is the charge multiplied after 3 hours?

   0.512
7. 7.

   Tala's video has V = 800(1.2)^d views. In this expression, what is (1.2)^d?

   • a term of the whole expression, separate from the 800
   • a constant number that stays fixed
   • two separate terms of the expression, 1.2 and d
   • a factor of the single term 800(1.2)^d
8. 8.

   Zee's card shows 3(x + 4)² − 5. What is (x + 4)² in this expression?

   • a term of the whole expression, separate from the 3
   • a constant number that stays fixed
   • two separate terms of the expression, x² and 16
   • a factor of the term 3(x + 4)²
9. 9.

   Ari's card shows (x + 2)(x − 5) + 7x. What is x − 5 in this expression?

   • a constant number that stays fixed
   • two separate terms of the expression, x and −5
   • a factor of the term (x + 2)(x − 5)
   • a term of the whole expression, separate from x + 2
10. 10.

    Bo's card shows 6(2x − 1) − 4(2x − 1). What is 2x − 1 in this expression?

    • a constant number that stays fixed
    • a term of the whole expression, separate from the 6 and 4
    • a factor of both terms
    • two separate terms of the expression, 2x and −1