Answer:
a = 51
b = 51 (??not so sure)
c = 20 cents
Step-by-step explanation:
a) 25 x 408 = 10200
10200 ÷ 200 = 51 square ft is one one roll.
b) the surface area of an average gift is 51 sq ft (?)
c) 40 ÷ 200 = 0.2
each roll costs $40 dollars. each roll can wrap 200 gifts so 40 ÷ 200 = $0.20/ 20 cents
F=v+at
f-v=at
(f-v)/t =a
the first choice is correct :)
varies directly means 
inserting y = -18 and x = 3 ⇒
⇒ -6 = k
next, insert k = -6 into the varies directly equation and solve for y. y = -6x
Answer: C