Soluzione - Problema delle parole

2 sentences contain the information we are after.

The first, [The sum of the 2 numbers is 20], we learn that:

There are 2 numbers we are looking for, as we don't know what they are, we will refer to them as $$x$$ and $$y$$.

The sum of $$x$$ and $$y$$ is 20. This can be mathematically expressed as $$x+y=20$$

A partir de la siguiente frase, [the product of the 2 numbers is 100], aprendemos que la product de $$x$$ y $$y$$ es igual a 100.

Esta información, puede expresarse en otra ecuación, que sería $$x\cdot y=100$$

Ahora tenemos un sistema de ecuaciones:

$$x+y=20$$
$$x\cdot y=100$$