Answer:
Part 1) 
Part 2) 
Part 3) 
Part 4) 
Part 5) 
Part 6) 
Step-by-step explanation:
Part 1) we know that
The shaded region is equal to the area of the complete rectangle minus the area of the interior rectangle
The area of rectangle is equal to

where
b is the base of rectangle
h is the height of rectangle
so



Part 2) we know that
The shaded region is equal to the area of the complete rectangle minus the area of the interior square
The area of square is equal to

where
b is the length side of the square
so



Part 3) we know that
The area of the shaded region is equal to the area of four rectangles plus the area of one square
so



Part 4) we know that
The shaded region is equal to the area of the complete square minus the area of the interior square
so



Part 5) we know that
The area of the shaded region is equal to the area of triangle minus the area of rectangle
The area of triangle is equal to

where
b is the base of triangle
h is the height of triangle
so



Part 6) we know that
The area of the shaded region is equal to the area of the circle minus the area of rectangle
The area of the circle is equal to

where
r is the radius of the circle
so


Could you maybe add more info? like a story or something
Answer:
$32.39
Step-by-step explanation:
She has a 15-gallon tank and it has 1/5 a tank of gas left (so about 3/15)
Because she needs to refill it and already has 1/5, she'll only need to pay for 4/5 a tank of gas (12/15).
So the equation should be 12 times $2.699.
12 × 2.699 = 32.388
Then, round to the nearest cent.
32.388 = $32.39
Hope this helped !
Solving
S = 3F - 24
for F gives
S + 24 = 3F
(S + 24)/3 = F
The best choice is the last one:
F = (S + 24)/3