Answer:
Step-by-step explanation:
Pi is the ratio of a circle's circumference to its diameter.
The circumference = π * the diameter of the circle (Pi multiplied by the diameter of the circle)
Hope this helps!
Answer:
The solution is 
Step-by-step explanation:
You are given the system of three equations:

Multiply the first equation by 4, the second equation by 3 and subtract them. Then multiply the third equation by 2 and subtract it from the second equation:

So,

Multiply the third equation by 23 and subtract it from the second equation:

Hence,

Substitute it into the second equation:

Substitute them into the first equation:

The solution is 
Answer:
720
Step-by-step explanation:
hope this helps