Answers:
section A = 25,000 seats
section B = 14,200 seats
section C = 10,800 seats
Your teacher may want you to leave out the commas from each number.
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Work Shown:
- A = number of seats in section A
- B = number of seats in section B
- C = number of seats in section C
A = B+C
A+B+C = 50,000
B+C+B+C = 50,000
2(B+C) = 50,000
B+C = 50,000/2
B+C = 25,000
C = 25,000 - B
25A + 20B + 15C = 1,071,000
25(B+C) + 20B + 15C = 1,071,000
25(25,000) + 20B + 15(25,000 - B) = 1,071,000
625,000 + 20B + 375,000 - 15B = 1,071,000
1,000,000 + 5B = 1,071,000
5B = 1,071,000 - 1,000,000
5B = 71,000
B = (71,000)/5
B = 14,200 is the number of seats in section B
C = 25,000 - B
C = 25,000 - 14,200
C = 10,800 is the number of seats in section C
A = B+C
A = 14,200 + 10,800
A = 25,000 is the number of seats in section A
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Check:
A+B+C = 25,000+14,200+10,800 = 50,000
on your calculator. Also make sure the calculator is in degree mode. You should get 23.32°