Problem
to calculate a seller's rating, $R$, based on the number of favorable reviews, $F$, and unfavorable reviews, $N$. Which of the following expresses the number of favorable reviews in terms of the other variables? A) $F=\frac{R N}{R-1}$ B) $F=\frac{R N}{1-R}$ C) $F=\frac{N}{1-R}$ D) $F=\frac{N}{R-1}$
Solution
Step 1 ：1. Start with the given equation for the seller's rating: \(R = \frac{F}{F + N}\)
Step 2 ：2. Solve the equation for F in terms of R and N: \(F = \frac{R N}{R-1}\)
Step 3 ：3. The final answer is: \(\boxed{F=\frac{R N}{R-1}}\)
