Answer:
Step-by-step explanation:
The $50 cleanup fee is a "fixed cost."
The "$30 per-person fee is a "variable cost." That is, it varies with the number of people.
"within" means "less than or equal to"
Cost = $50 + $30x [where x = number of people]
Cost ≤ $4500 ["stay within their budget"]
$50 + $30x ≤ $4500 [substitute for cost]
$30x ≤ $4450 [subtract $50 from both sides retains sense of inequality]
x ≤ 148.3333 [divide by +$30 retains sense of inequality]
Mark and Heather may invite up to 148 guests.
[note: to be "≤," always truncate, never round up]
Check:
148 people for $30 each + $50 is $4440+$50 = $4490.
One more person makes it $4520 -- that is too much.
There we go, my bad
