Answer:
15%
Step-by-step explanation:
Let c represent the regular price of the carpet.
Then:
sale price = regular price less discount
$374 = c - $66
Adding $66 to both sides isolates (solves for) c:
$374 + $66 = c = $440. This is the regular price.
$66
---------- = 0.15 This is the fraction of the regular price by
$440 which the regular price is reduced.
Then the percentage of this discount was 0.15(100%) = 15%
is in quadrant I, so
.
is in quadrant II, so
.
Recall that for any angle
,

Then with the conditions determined above, we get

and

Now recall the compound angle formulas:




as well as the definition of tangent:

Then
1. 
2. 
3. 
4. 
5. 
6. 
7. A bit more work required here. Recall the half-angle identities:



Because
is in quadrant II, we know that
is in quadrant I. Specifically, we know
, so
. In this quadrant, we have
, so

8. 
Hello,
A=(4,2)
B=(2,8)
(AB)≡y-2=(x-4)*(8-2)/(2-4) ==> y=-3x+14
(BC)≡y-8=(x-2)*1/3 ==> y=1/3 x+22/3