Arithmetic I'm pretty sure
6) check picture
a) all three lines are parellel and have the same slope. the only difference is that they are translated on different points on the x-axis.
not sure about the rest sorry :(

The multiple zero is x = -4.
The multiplicity is 2 because there are two values of x.
(x-3)(x+4). -3,4 multiply to -12, and add to get 1