The appropriate choice is ...
C. The slope of the first equation is not graphed the right way.A correct graph is shown below.
1. $129.60
2. $109.90
3. $66.10
You still want at most
(15x) + (22y) ≤ 100(-z) (equation used)
0 ≤ z ≤ 10 (amount you want to leave unspent)
y ≥ 1 (amount of dress shirt you need)
This is your system of equation, in which the numbers must fulfill both equations
hope this helps
See my answer to the other posting of the same question.
Answer:
The center of the tetrahedron divides each of the four heights (or medians) in the ratio 1:3 (in an equilateral triangle the corresponding ratio is 1:2). The smaller part is also the radius of the inscribed sphere. Therefore the radius of this sphere is one quarter of the height or 9 in your case.