Answer:
Juan has € 6 and Laura has € 10
Step-by-step explanation:
Juan has x €, Laura has y €.
Juan says to his sister Laura: "If you give me 2 euros, we will have the same amount of money."
Juan will then have x + € 2 and Laura will keep y - € 2.
That is to say:
x + 2 = y - 2
y = x + 4
Laura replies to Juan: "If you give me 2 euros, I will have triple what you do."
Laura would have this time y + € 2, and Juan x - € 2
3 * (x - 2) = y + 2
3 * x - 6 = y + 2
we substitute the y = x + 4 of the first equation:
3 * x -6 = x + 4 + 2
3 * x -6 = x + 6
We gather the x:
3 * x - x = 6 + 6
2 * x = 12
x = 12/2 = € 6
y = x + 4 = 6 + 4 = € 10
Therefore Juan has € 6 and Laura has € 10