Solve a formula for one letter

Answer Key - Grade 9 Math Worksheet - Challenge Me

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

1. 1.

   A trapezoid pond has area A = (1/2)h(b + c). Ren wants b. Solve A = (1/2)h(b + c) for b.

   b = 2A/h − c
2. 2.

   Tala's rug has perimeter P = 2(l + w). Solve P = 2(l + w) for l.

   l = P/2 − w
3. 3.

   Row 1 has a seats, and each row has d more, so row n has L = a + (n − 1)d. Zee solves for n.

   n = (L − a)/d + 1
4. 4.

   Ari's pyramid has volume V = (1/3)Bh, with base area B. Solve V = (1/3)Bh for h.

   h = 3V/B
5. 5.

   The mean of two scores is m = (a + b)/2. Bo knows m and a. Solve m = (a + b)/2 for b.

   b = 2m − a
6. 6.

   Jun's bike picks up speed with a = (v − u)/t. Solve a = (v − u)/t for v.

   v = at + u
7. 7.

   Kira rides d = 4t + 20 meters from home after t minutes. When d = 56, what is t?

   9
8. 8.

   Luz's game scores Q = 6b + 4c: big stars b are worth 6, small stars c are worth 4. Q = 54 and c = 3. What is b?

   7
9. 9.

   Milo's scooter speeds up by v = u + at. The start speed is u = 4, v = 16 and a = 2. What is t?

   6
10. 10.

    Noah's game gives N = 5c − 12 points for c coins. Noah scored N = 63. How many coins is c?

    15