The answer to the f(x) is D f(x) = 3x + 3 because (x,y) you input x into the equation and you get y, if that makes sens, u said u need it now so I won't go into it too much.
Step-by-step explanation:

Volume of rectangular prism = 1 1/3 x 5/6 x 2/3 = 4/3 x 5/6 x 2/3 = 20/27
Volume of cube = 1/6 x 1/6 x 1/6 = 1/216
Number of cubes that will pack the rectangular prism = 20/27 / 1/216 = 160
As AB and ED are parallel, they have the same slope. This means that since lines that are colllinear with parallel segments are parallel, lines l and m are parallel.