The factored form would be (3x-9)(x-1)
The picture should help a bit
r is the x coordinate and s is the y coordinate. Positive slopes go from lower left to upper right, like going up stairs or up a hill. The line that goes through (r, s) that is positive is line B.
Y2 -y 1 / x2 - x1
6 - 4 / -1 - 2
2 / - 3
m = -2/3 x (slope)