The number of seats sold cannot be negative, so you have
... x ≥ 0, y ≥ 0
The limits on numbers of seats must be observed, so you have
... y ≤ 2000
... x + y ≤ 3000
And the revenue constraint must be met:
... 35x + 50y ≥ 90,000
Together, these inequalties are ...
{x ≥ 0, y ≥ 0, y ≤ 2000, x + y ≤ 3000, 35x + 50y ≥ 90,000}
|4r + 8| ≥ 32
Split this expression into two expressions:
First ⇒ 4r + 8 ≥ 32 and second ⇒ 4r + 8 ≤ - 32
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First expression: 4r + 8 ≥ 32
Subtract 8 from both sides.
4r ≥ 24
Divide both sides by 4.
r ≥ 6
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Second expression: 4r + 8 ≤ - 32
Subtract 8 from both sides.
4r ≤ -40
Divide both sides by 4.
r ≤ -10
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Your answer is 
Answer:
20 points
Step-by-step explanation:
Points:
- 21, 13, 14 and x for the last game
Average:
- (21+13+14+x) / 4 = 17
- 48 + x = 4*17
- 48 + x = 68
- x = 68 - 48
- x = 20
They must score 20 points
Your answers we equal to 22