Mathematics for IGCSE & O level - Equations (Section 4 - No. 22)
Write an equation for the statement: The cost (C) of renting a car is a fixed charge (K) plus the number of days (d) multiplied by the daily rate (R).
C = K + dR
C = d + KR
C = K - dR
K = C + dR
Explication
The correct formula represents the total cost as the sum of the fixed charge and the variable cost (daily rate times the number of days).