sub 780 for x
-2,5x^2 +2825x -115,812.5
-2,5*780^2 + 2825*780 - 115,812.5
Is there a typo in -2,5? Evidently you use a period for the decimal point later on.
-2,5x^2 +2825x -115,812.5
Is there a typo in -2,5? Evidently you use a period for the decimal point later on.