The equation of the sphere centered at 0, and radius 4 is:

,
note that this equation describes exactly the points of the surface of the square. That is, this is an EMPTY sphere.
The solid sphere, that is the points on the surface and all points in the inside, are given by :

since we want the left part of the solid part, picture 2, we add the condition x<0,
thus "the solid left (x < 0 is left) hemisphere of a sphere of radius 4 centered at the origin" is given by the system of inequalities:

In the problem, how do you get 6,300,000 using the digits 1-7 to create a
seven-digit number that can be rounded to 6,300,000.
We can use the numbers according to the rule of rounding values, 0-4 and
5-9.
Hence the numbers are:
1. 6, 290,000 = 6, 300, 000
2. 6, 310, 000 = 6, 300, 000
Therefore the numbers concerned in the given value is in the place order of
ten thousand which will determine the hundred thousands’ value.
Answer:
Store C
Step-by-step explanation:
Simply divide the price by the amount to determine which store has the best price efficiency.
A : 12.99 / 100 = .129¢ per oz
B : 9.49 / 70 = .136¢ per oz
C: 10.98 / 90 = .122¢ per oz
Store C has the best price efficiency
I think the expression for that is 13 • h • 3 because he gets $13 per hour and we don't know how many hours he worked so we would just put a variable and then he worked three times as many hours so multiply by 3. I might be wrong but hopefully it helps