1. Let's identify the expressions based on the diagram. 2. The top two purple boxes are $5d + 2f$ and $3d + 4f$. 3. The addition of these two gives $B$: $$B = (5d + 2f) + (3d + 4f) = 5d + 3d + 2f + 4f = 8d + 6f$$ 4. $A$ is connected to $5d + 9f$ via an addition node, therefore the expression $A$ must be $5d + 9f$. 5. The bottom-center addition node connects $B$ and $5d + 9f$ to give $C$: $$C = B + (5d + 9f) = (8d + 6f) + (5d + 9f) = 8d + 5d + 6f + 9f = 13d + 15f$$ Final expressions: - $A = 5d + 9f$ - $B = 8d + 6f$ - $C = 13d + 15f$