To find out how many additional people attended Leslie's birthday party, we can use the given linear function model for total cost:
\[ b(x) = 100 + 15x \]
where:
- \( b(x) \) is the total cost,
- \( 100 \) is the initial space rental fee,
- \( 15 \) is the cost per person, and
- \( x \) is the number of people attending.
Leslie received a bill of $550, so we can set the equation:
\[ 100 + 15x = 550 \]
Now, we can solve for \( x \):
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Subtract 100 from both sides: \[ 15x = 550 - 100 \] \[ 15x = 450 \]
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Divide both sides by 15: \[ x = \frac{450}{15} \] \[ x = 30 \]
Since the problem states that Leslie and Steve are attending, we have to add them to the number of additional people:
- Total attendees, \( x \), is 30.
- Given that Leslie and Steve are 2 people, the number of other people attending will be: \[ 30 - 2 = 28 \]
Therefore, the number of other people who attended the birthday party is 28.