Answer
Candlestick Park has 70200 seats.
Cowboy Stadium has 80000 seats.
Soldier Field has 61500 seats.
Work Step by Step
Let x represent the number of seats in Candlestick Park.
Number of seats in Cowboy Stadium: x+9800
Numbero f seats in Soldier Field: x-8700
The total number of seats: 211700
(x+9800)+(x-8700)+x=211700
3x=210600
x=70,200
Candlestick Park has 70200 seats.
Cowboy Stadium has 80000 seats.
Soldier Field has 61500 seats.