For the first one we see that the shape is that of a parabola and is translated down a few units, We can eliminate linear, exponential and looking at the general shapes of quadratic and polynomial functions we can conclude that the graph is from a quadratic equation
Answer: Factors of 400 = 1, 2, 4, 5, 8, 10, 16, 20, 25, 40, 50, 80, 100, 200 and 400. Factors of 401 = 1 and 401. Hence, the common factor of 400 and 401 is 1.