X and y are sets of coordinates you can use to determine the slope.
1. y=mx+b
2. y2-y1/x2-x1
For the first problem you can plug in (3,11) and (6,17) to the second formula.
(17-11)/(6-3)
6/3 = 2
Thus, your slope is 2.
To find y-intercept you would substitute a pair of coordinates into y=mx+b
11=3(2)+b
b=5
y=2x+5
