The surface (call it
) is a triangle with vertices at the points



Parameterize
by

with
and
. Take the normal vector to
to be

Then the flux of
across
is



Part A: first multiply 2 by x and -3, then combine the like terms, after that add 6 from both sides, then subtract 6x from both side, the answer is -5.
4x + 2(x-3) = 4x + 2x - 11
4x +2x -6 = 4x + 2x - 11
6x -6 = 6x - 11
6x = 6x -11 +6
6x = 6x -5
6x-6x= -5
0 = -5
part B) add the like terms
The app photo math is really awesome,
I Hope this Helps!