math
posted by dan .
The larger circle has a radius that is 18 inches longer than the smaller circle. The larger circle has a circumference that is A pi feet larger then the smaller circle. find the value of a.

Radius of smaller circle: a18 (inchs)
Radius of larger circle: a (inchs)
Circumference of smaller circle:
2*pi*(a18)=2*pi*a2*pi*18=2*pi*a36*pi (inchs)
Circumference of larger circle:
2*pi*a (inchs)
Difference betwen ircumference of smaller and large circle:
D=2*pi*a(2*pi*a36pi)=
2*pi*a2*pi*a+36pi=
36*pi (inchs)
D=36*pi (inchs)
1feet=12 inchs
D=(36*pi)=(3*pi)ft
D=(A*pi)
A*pi=3*pi Divide with pi
A=3 
D=(36*pi)in=(3*pi)ft