Answer:
$24
Step-by-step explanation:
First, find the cost to cover one pair of shoes.
Cost to cover one pair of shoes = surface area of the shoe box × cost per square inch
= 2(LW + LH + HW) × 0.02
L = 14 in.
W = 8 in.
H = 4 in.
Plug in the values
Cost to cover one pair of shoes = 2(14*8 + 14*4 + 4*8) × 0.02
= 2(112 + 56 + 32) × 0.02
= 2(200) × 0.02
= 400 × 0.02 = 8
Cost to cover one pair of shoes = $8
Cost to cover 3 pairs of shoes = 3*8 = $24
Answer:
Line AB is Perpendicular to line CD
Line AB Parallel to line EF
Use the sum of cubes factoring rule

to transform the left hand side into the right hand side.


Throughout the entire process, the right hand side stayed the same.
On the last step, I used the pythagorean identity.
Since a calculator is involved in finding the answer, it makes sense to me to use a calculator capable of adding vectors.
The airplane's ground speed is 158 mph, and its heading is 205.3°.
_____
A diagram can be helpful. You have enough information to determine two sides of a triangle and the angle between them. This makes using the Law of Cosines feasible for determining the resultant (r) of adding the two vectors.
.. r^2 = 165^2 +15^2 -2*165*15*cos(60°) = 24975
.. r = √24975 ≈ 158.03
Then the angle β between the plane's heading and its actual direction can be found from the Law of Sines
.. β = arcsin(15/158.03*sin(60°)) = 4.7°
Thus the actual direction of the airplane is 210° -4.7° = 205.3°.
The ground speed and course of the plane are 158 mph @ 205.3°.