I assume
has counterclockwise orientation when viewed from above.
By Stokes' theorem,

so we first compute the curl:


Then parameterize
by

where the
-component is obtained from

with
and
.
Take the normal vector to
to be

Then the line integral is equal in value to the surface integral,



The slope of this triangle is -2/1
Answer:
what? I don't get it?
Step-by-step explanation:
80+10x is the expression. To find the cost for 9 guests, simply plug in 9 for x. This becomes an equation reading 80+10(9)=170. The total cost for 9 guests is $170.00.