### lcm

Returns the least common multiple of two numbers.

Use the greatest common divisor (GCD) formula and `Math.abs()` to determine the least common multiple.
The GCD formula uses recursion.

```js
const lcm = (x, y) => {
  const gcd = (x, y) => (!y ? x : gcd(y, x % y));
  return Math.abs(x * y) / gcd(x, y);
};
```

```js
lcm(12, 7); // 84
```