Consider the 4 points A(1,5), B(-4,6), C(0,0), D(-12,12). Find the gradients of the lines:
(a) AB;
(b) CD;
(c) BD.
One of the most basic concepts in this topic is "finding the slope between two points"
Your text and notes MUST contain the steps
I will do the first one, you do the rest
slope = (y2-y1)/(x2-x1)
= (6-5)/(-4-1)
= 1/-5 or - 1/5