1)
rearrange to nice form:
2y - x = 4
2y = x + 4
y = 0.5x + 2
so, y = 0 when x = -4
x = 0 when y = 2
(by plugging the numbers in)
gradient, uh, well, by converting the equation into the above format we know the grad is a half. or, you can take the two points you know, (-4,0) and (0,2), and then find change in y over change in x.