Answer:
16. 
17. 
18. 
19. 
Step-by-step explanation:
Equation is 
where k is a constant of proportionality.
16.
So, equation is
17.
Equation is
18.
Equation is
19.
Equation is
28. Surface Area
This is some sort of house-like model so for every face we see there's a congruent one that's hidden. We'll just double the area we can see.
Area = 2 × ( [14×9 rectangle] + 2[15×9 rectangle]+[triangle base 14, height 6] )
Let's separate the area into the area of the front and the sides; the front will help us for problem 29.
Front = [14×9 rectangle] + [triangle base 14, height 6]
= 14×9 + (1/2)(14)(6) = 14(9 + 3) = 14×12 = 168 sq ft
OneSide = 2[15×9 rectangle] = 30×9 = 270 sq ft
Surface Area = 2(168 + 270) = 876 sq ft
Answer: D) 876 sq ft
29. Volume of an extruded shape is area of the base, here the front, times the height, here 15 feet.
Volume = 168 * 15 = 2520 cubic ft
Answer: D) 2520 cubic ft
Well
if it is marked 1/3 off, then you're actually paying 2/3 of it.
2/3 of 123. " of " means multiply
2/3 * 123 = 246/3 = 82 So it now costs $ 82
Since density is the ratio of mass to (in this case) area, we can find the mass of the triangular region 
by computing the double integral of the density function over :
The boundary of is determined by a set of lines in the 
plane. One way to describe the region is by the set of points,
So the mass is
The equivalent to 4/5 is 0.8.
