4) B.
No equation is given, so there is no "solution". The solution to f(x) = 0 is found where the graph crosses the x-axis. You have to read the graph to find these points as (-3, 0) and (2, 0), so "solutions" are -3, 2.
5) B.
All quadratic functions have two zeros. The two zeros for this function are identical (±0), so are usually counted as one (distinct) zero.
6) C.
(-b±√(b^2-4ac))/(2a) = (3±√(9+40))/2 = (3±7)/2 = {-2, 5}
7) B.
The product of the roots (-6) is the constant term. The sum of the roots (1) is the negative of the x-coefficient. You are looking for x^2 -1x -6 = 0
