A concert promoter sells x ticket and has a marginal$-$profit function given

byP$=4$x$45"$ role$=$"presentation" style$=$"display: inline$-$block; font$-$style: normal; font$-$weight: normal; line$-$height: normal; font$-$size: $24$px; text$-$indent: $0$px; text$-$align: left; text$-$transform: none; letter$-$spacing: normal; word$-$spacing: normal; overflow$-$wrap: normal; white$-$space: nowrap; float: none; direction: ltr; max$-$width: none; max$-$height: none; min$-$width: $0$px; min$-$height: $0$px; border: $0$px; padding: $0$px; margin: $0$px; position: relative;"$>=445$

where is in dollars per ticket. This means that the rate of change of total profit with respect to the number of tickets sold x is $.$ Find the total profit from the sales of the first $80$ tickets.