ITPEC FE Subject A April 2026 Question 1

Prefix notation — the operator is written before its two operands, so convert outward from the innermost parentheses.

The expression is ((a-b)/(c+d))^e. Convert bottom-up:

• •a-b → -ab
• •c+d → +cd
• •(a-b)/(c+d) → division of the two results → /-ab+cd
• •the whole thing raised to e → ^/-ab+cde

Answer (c): ^/-ab+cde

Why not others:
- (a) ^e/+dc-ba — every pair of operands is reversed; in prefix only the operator moves, operand order stays as written
- (b) ^-ab/+cde — places -ab directly under ^, which reads as (a-b) raised to something and loses the division
- (d) ^e/-ab+cd — puts e right after ^, making e the base instead of the exponent

Key rule: Convert the deepest parentheses first, then treat each converted group as a single operand. Operand order never changes — only the position of the operator does.

AI-generated — may contain errors