Add, subtract, multiply, and divide fractions. Results are simplified automatically.
Addition: a/b + c/d = (ad + bc) / bd, then simplify by dividing by the GCD.
Subtraction: a/b - c/d = (ad - bc) / bd, then simplify.
Multiplication: a/b x c/d = ac / bd, then simplify.
Division: a/b / c/d = ad / bc (multiply by the reciprocal), then simplify.
Simplification uses the Greatest Common Divisor (GCD) to reduce the fraction to its lowest terms.