Answer:
A=R/CD
Explanation:
AC=R/D
--Multiply by d on both sides to get rid of the fraction on right side
D*AC=R/D *D
--d on the denominator is canceled out.
ACD=R
--divide ACD by CD to isolate A.
ACD/CD = R/CD
--CD on numerator and denominator cancel out. A is found.
A=R/CD