Edward C. answered 04/23/15
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Let X = number of hours that Shaggy worked
Let Y = Shaggy's earning in dollars
Shaggy earned $75 in tips plus $8.25 per hour. This means that he earned $8.25 times the number of hours that he worked, plus $75. You can write this as an equation
Y = 8.25*X + 75
We don't know exactly how much Shaggy earned but we know it was at least $200. So
Y ≥ 200
8.25*X + 75 ≥ 200 (since Y = 8.25*X + 75)
8.25*X ≥ 125 (subtracted 75 from both sides)
X ≥ 15.15 (divided both sides by 8.25)
To make sure Shaggy's earning are at least $200 you have to round up to X = 16 hours
Check: 8.25*16 + 75 = 132 + 75 = $207 which is at least $200
8.25*15 + 75 = 123.75 + 75 = $198.75 which is not at least $200