X = number of cds on the rack
x + 7 = 30
x = 30 - 7
x = 23 <== so there are currently 23 cds on the rack
It will be -200 kilometers because you gotta get a ruler
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Doubling the radius of the cylinder will quadruple the volume.
Answer:
Volume of a cylinder.
Step-by-step explanation:
The given equation is :

Where
r is the radius
h is the height
This equation is used to find the volume of a cylinder.
For example, a cylinder having radius of 7 units and height of 10 units, its volume will be :

So, the given equation is used to find the volume of a cylinder.