Matemática tema: máximacion y minimizacion

el dueño de un campo de 10 hectáreas planta limoneros sabe estadisticamente que si planta 40 limonero por hectárea cada uno de ello le dará 120 limones pero por cada limonero de más que plante esto dara 2 limones
cuantos limones deberé plantar para obtener la mayor cantidad de limones? ?
por me ayudan es para mañ

Aquadratic function f(x) has a turning point at (3,-7). what is the turning point of -f(x)?

Sam makes his sales calls according to a pattern. he travels either north or south depending on the calendar. some of his past trips were as follows: on february 17, april 24, june 10, september 19, and november 3 he drove north. on february 28, may 25, august 22, november 20, and december 18, he drove south. describe sams' pattern. in which direction will sam drive on oct4 and oct 24?

Find the domain of the following expression: 1/(√x)-2