Closures — Make Multiplier

Implement solve(factor, x) that creates a closure internally and uses it to return x * factor.

Specifically, inside solve:
1. Define an inner function multiplier(n) that returns n * factor.
2. Return multiplier(x).

This ensures you practice writing closures — the inner function must capture factor from the enclosing scope.

Examples

solve(2, 5)   # → 10   (2 × 5)
solve(2, 10)  # → 20   (2 × 10)
solve(3, 7)   # → 21   (3 × 7)