Need to know the surface area me figure out how to solve it

What is the vertex form of f(x) = x2 + 6x + 3

Determine the fraction of total interest owed. after the fourth month of a 12-month loan: the numerator is: {(n + ) + (n + ) + (n + ) + (n + )} = , and the denominator is: {(n) + (n + 1) + + (n + )} = . therefore, the fraction is numerator/denominator (to the nearest tenth) =

Given f(x)= 9x+1 and g(x)=x^3, choose the expression (f*g)(x)