Answer: 
Step-by-step explanation:
Let w denotes a seven letter word which Sal will need to make to break the record.
Since you get 50 points for each seven-letter and 100 points for playing the game.
Then the total points earned by you by making w seven letters words will be:

Since, Sal wants to break that record, and needs 18,000 points or more to do so.
Then , the required inequality will be :

<h3>
Answer: 1260</h3>
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Work Shown:
n = number of sides = 9
S = sum of the interior angles of any polygon with n sides
S = 180(n-2)
S = 180(9-2)
S = 180(7)
S = 1260
X = tuna, y = BLT
x + y = 30
6x + 9y = 240
3y = 60
y = 20
x = 10
20 BLTs for $2.50, 10 tuna for $1.50
Here is the answer, with a picture of how you do it:)