When you see questions of this nature, test the individual inequalities and look out for their intersection.
For

Choose a point in the lower or upper half plane created by the line

The above line is the one which goes through the origin.
Now testing (1,0) yields,

That is,

This statement is true. So we shade the lower half of

For

We test for the origin because, it is not passing through the origin.

This yields

This statement is false so we shade the upper half.
The intersection is the region shaded in B. The top right graph
A cube has six sides so you divide 3750 by 6 to find the area of a single face. This would be 625. Area is length times width and since it is a cube you know that both are the same. This gives you an answer of 25.
Answer:
36 in³
Step-by-step explanation:
Volume of cylinder = pi×r²×h
Volume of cone = ⅓×pi×r²×h
For same r and h,
Volume of cone is ⅓ of the Volume of cylinder
⅓ × 108 = 36
2400 + 100x = 2200 + 120x
2400 - 2200 = 120x - 100x
200 = 20x
200/20 = x
10 = x <== they would have to sell 10 systems