Hello, I would like the answer to this question please

1-Consider the following demand and supply model where firms receive a subsidy S for every unit they sell. Demand and supply functions are therefore given by Qd=D(p) and Qs=S(p+S) where / is the unit price. At the equilibrium quantity demanded * and price * , choose all the correct answers below. 2- If f( X) is locally concave at X=XO, then fin(Xo) sol H 3-Find the value of XE [O,3] that gives maximum value of f(X) =3X2-6X+5. 4-If f(x)=0 at x=Xo and f.(Xo)