ubtracts two rational numbers represented as numerator and denominator

What will be an ideal response?

```
( int& ansNum, int& ansDenom,
int num1, int denom1,
int num2, int denom2 )
{
int greatest;

ansDenom = denom1 * denom2;
ansNum = num1 * denom2 - num2 * denom1;
greatest = gcd( ansNum, ansDenom );
ansNum /= greatest;
ansDenom /= greatest;
}

```