Alright, so first we need to establish two things.
First, the compliment of a set is like the extreme opposite; everything that is not in set B will be in the complement.
Second, we need to find out what B is.
Okay, so B is everything that is greater than 2, that's given. That includes 3, 4, and 5. B = {3, 4, 5}. There are three items in this set.
The numbers that aren't included are 1 and 2. The complement of B, let's call this C I guess, is C = {1, 2}. There are 2 items in this set.
The answer, I believe, is <em>two</em>. Hope this helps!
In order to determine whether the equations are parallel, perpendicular, or neither, let's simply each equation into a slope-intercept form or basically, solve for y.
Let's start with the first equation.

Cross multiply both sides of the equation.


Subtract 6x on both sides of the equation.


Divide both sides of the equation by -5.


Therefore, the slope of the first equation is 4/5.
Let's now simplify the second equation.

Add x on both sides of the equation.


Divide both sides of the equation by -4.


Therefore, the slope of the second equation is -5/4.
Since the slope of each equation is the negative reciprocal of each other, then the graph of the two equations is perpendicular to each other.