He divided the wrong way. 7/33 = .2121.....and 2/11 = .1818...., so actually 2/11 < 7/33
Slope = (y2 - y1)/(x2 - x1)
slope = (-3 -4)/(1 - 1)
slope -7/0
This is an undefined slope because the denominator is 0.
This would be a vertical line.
4 1/4 % =
4.25% =
0.0425 =
425/10,000 =
17/400 <==
First of all, expand the left hand side:

Sum like terms:

Add 3 to both sides:

Subtract 3x from both sides:

So this is the solution. Every number smaller than 8 (excluded) is part of the solution of this inequality.