Answer:
<em>$83.69</em>
Step-by-step explanation:
Given the following
Initial Cost of the brunch = $72.80
Percentage tip = 15%
Tip paid = 15% of $72.60
Tip paid = 0.15 * 72.60
Tip paid = $10.89
Total cost of brunch = $72.80 + $10.89
Total cost of brunch = $83.69
<em>Hence the total cost of her brunch is $83.69</em>
X - number of customers

There can't be a fraction of the number of people, so there must be some mistake in the question.
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Answer:
y = 5x
Step-by-step explanation:
If each calendar, <em>x</em>, sells for $5 each, you would multiply 5·x because $5 is how much you earn per calender. Therefore, your total income would be 5 times the number of calendars you sell, or in equation "language", y = 5x
F(-2)=2(4)
-2=8
— —
-2 -2
F=-4