please help on the following.

production function of Selina's bakery is: | N f(x1,x2)=x x IUI Nulll where 111 is the amount of flour she uses and x2 is the amount of butter she uses, wl = $2 and w2 = $14 If Selina wants to bake 100 units of cakes, what is the profit maximizing amount of flour required