<h2>
Greetings!</h2>
Answer:
y =
and x = 
Step-by-step explanation:
To solve simultaneous equations, you need to have the number in front of both x's or y's the same. (signs doesn't matter)
To get -x to -10x we simply need to multiply the first equation by 10:
-x * 10 = -10x
-9y * 10 = -90y
16 * 10 = 160
-10x - 90y = 160
Now we can add the two equations:
-10x + 10x = 0
-90y + 20y = -70y
160 + 20 = 180
-70y = 180
70y = -180
7y = -18
y = 
Now plug
into the second equation:
10x + 20(
) = 20
10x -
= 20
Move the
over to the other side, making it a positive:
10x = 20 + 
10x = 
Divide both sides by 10:
x = 
So y =
and x = 
<h2>Hope this helps!</h2>
Answer: D) Flat area with a large number of plants
The roots of the plants hold in the soil, which prevents/reduces erosion.
The steeper slope means gravity pulls down the soil material faster, since there is less ground in the way to hold it up, so to speak. So flatter areas are less prone to erosion compared to steeper areas.
So that's why overall, flatter areas with lots of plants would have the least erosion.

Converting to spherical coordinates, we have

On the other hand, we can parameterize the boundary of

by

with

and

. Now, consider the surface element



So we have the surface integral - which the divergence theorem says the above triple integral is equal to -


as required.