Answer:
The slope of a line is
[tex] \frac{y2 - y1}{x2 - x1} [/tex]
Get 2 points off each line
(x1, y1)
(x2, y2)
And sub them into the formula.
The y intercept is where the line cuts the y axis (the vertical line)
From what I can make out the y intercept for the first part in question 12 is (0,-2) and for the third part is (0,0) but I can't see the second one.
It might help if you took a clearer photograph I'm so sorry but I can't really see it.
