public fraction add(fraction x) {
BigInteger gcd = den.gcd(x.den);
BigInteger A = x.den.divide(gcd);
BigInteger B = den.divide(gcd);
BigInteger newNum = num.multiply(A).add(x.num.multiply(B));
BigInteger newDen = den.multiply(A);
fraction t = new fraction(newNum, newDen);
t.fix();
return t;
}
public fraction divide(fraction x) {
fraction t = new fraction(x.den.multiply(num), x.num.multiply(den));
t.fix();
return t;
}
public fraction subtract(fraction x) {
return this.add(x.negate());
}