Answer:
15 and a half days
Step-by-step explanation:
Since they earn $12's each day you would do $186 divided by $12 which would be 15.5 so it would take them 15 and a half days to raise $186.
First you must combine like terms, the two terms I this expression are x, and xy. So by adding -2xy to -2xy you get -4xy. Next you must add 3x to 3x. This gives you the simplified expression -4xy+6x. Hope this helps
Step-by-step explanation:

Find the critical points of
:


All three points lie within
, and
takes on values of

Now check for extrema on the boundary of
. Convert to polar coordinates:

Find the critical points of
:



where
is any integer. There are some redundant critical points, so we'll just consider
, which gives

which gives values of

So altogether,
has an absolute maximum of 65/16 at the points (0, -1/2) and (0, 1/2), and an absolute minimum of 3 at (-1, 0).
Answer:
1) 2 and 6 ; 4 and 8 ; 1 and 5 ; 3 and 7
2) 3 and 6 ; 4 and 5
3) 1 and 8 ; 2 and 7