A is the line that runs from 0,-6 to 5,14 This is tricky because the scale of the y-axis is twice the value of the x-axis. So what looks like a slope (gradient) of +2 is actually +4. Figure the difference in y-values divided by the difference in x-values.
Same for line B.
I used 0 - 14 for the rise, and 4 -(-3) for the run. 7/-14 makes that slope a -2. That's negative two, not the apparent negative one!
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