The answer is going to be A!!!
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.
Apparently my answer was unclear the first time?
The flux of <em>F</em> across <em>S</em> is given by the surface integral,

Parameterize <em>S</em> by the vector-valued function <em>r</em>(<em>u</em>, <em>v</em>) defined by

with 0 ≤ <em>u</em> ≤ π/2 and 0 ≤ <em>v</em> ≤ π/2. Then the surface element is
d<em>S</em> = <em>n</em> • d<em>S</em>
where <em>n</em> is the normal vector to the surface. Take it to be

The surface element reduces to


so that it points toward the origin at any point on <em>S</em>.
Then the integral with respect to <em>u</em> and <em>v</em> is



2x+10x combine like terms
12x
2(x-4)+4 Distribute 2
2x-8+4
combine like terms
2x-4