Answer:
d = 15 miles
Step-by-step explanation:
To get to his parents’ house, Ruben would have to drive due north 12 miles.
To get to his grandparents’ house, he would have to drive due east 9 miles.
It is required to find the distance between the parents’ and grandparents’ houses.
First distance is 12 miles and second distance is 9 miles.
So,
[tex]d=\sqrt{12^2+9^2} \\\\d=15\ \text{miles}[/tex]
So, the distance between the parents’ and grandparents’ houses is 15 miles.
