Determine and print expression to reach target

You are given four numbers and a target T (e.g., 24). Using +, −, ×, ÷ and parentheses, and using each number exactly once, determine whether you can form an expression that evaluates to T. Return a boolean. Follow-up: if it is possible, output one valid expression string. Clarify how to handle division by zero and floating-point tolerance; discuss algorithmic approach (e.g., backtracking with pruning), complexity, and how you would extend the method to N numbers or different operator sets.