Y = -x/3 + b1 = -3/3 + b
substitute values of point1 = -1 + b
then reduce2 = b
add one to both sides y = -x/3 + 2
A cube has equal edges, so 2*2*2 or 2^3 (2 cubed) v=8^3
"color the piece according to your color chart." Do you have that? If you don't, I wouldn't worry, you still did all the work and got all the answers, so your teacher should be fine with it.
Your y-intercept would be (0,-13)
