-8*21
= -168
Hope this helped
Answer: 
Step-by-step explanation:
The volume of a cylinder can be calculated with the following formula:

Where "r" is the radius and "h" is the height.
The volume of a sphere can be found with this formula:

Where "r" is the radius.
Then, volume of the empty cylinder is:

And the volume of the ball is:

Finally, you need to subtract them in order to calculate how much water is in the cylinder:

Answer:
A = 6.36
Step-by-step explanation:
Answer:
Width =9 cm
Length =6 cm
Step-by-step explanation:
Let x be width, then length is x − 3
Let area be E. Then we have: E = x ⋅ (x −3)
54= x^2-3x
x^2-3x-54=0
We then do the Discriminant of the equation:
D=9+216
D=225
X1=3+15 over 2. which is 9
X2= 3-15. over 2. which is -6 Which is declined, since we can't have negative width and length.
Therefore x is 9. So width
So width = x = 9cm and length is x-3 = 9-3cm=6 cm