Answer:
(-10,0)(-5,0)(-10,-10)(-10,-5)
Step-by-step explanation:
If we count each box as one unit then we just count and if you left or down it is negative
Looks like you have most of the details already, but you're missing one crucial piece.
is parameterized by

for
and
, and a normal vector to this surface is

with norm

So the integral of
is

Answer:
c
the total number of marbles are 12 and there are 3 colours so you divide 12 by 3