Answer:
Step-by-step explanation:
Its actually -6.9
Looks good! You have the right answers.
However, the graph for 12 and 15 is inaccurate! Because he starts from a stop sign/stop light, the graph's speed should start from the origin!
Not to confuse you or anything, but this means the graph does not follow the description of the problem. Please let your teacher know so s/he can fix the worksheet.
ANSWER
The sphere is 10762 cubic centimeters bigger than the cube.
EXPLANATION
We want to find the difference in the volumes of the sphere and the cube.
To do this, we have to find the volumes of the sphere and cube and subtract that of the cube from the sphere.
The volume of a sphere is given as:

where r = radius
The radius of the sphere is 15 centimeters. Therefore, the volume of the sphere is:

The volume of a cube is given as:

where s = length of the side
The length of the side of the cube is 15 centimeters. Therefore, the volume of the cube is:

Therefore, the difference in the volumes of the sphere and cube is:

Therefore, the sphere is 10762 cubic centimeters bigger than the cube.
After 12 hours the pound would have 720 pounds of algae.