In order to determine who lives closer to the school, use the following formula for the distance between two points (x1,y1) and (x2,y2):
d = √((y2 - y1)² + (x2 - x1)²)
The coordinates of the school are C(3,18) and the coordinates of Owen's house and David's house are, respectively, A(11,3) and B(15,13).
Calculate the distance in between points A and C, and B and C by using the formula for d:
distance AC:
d = √((3 - 18)²+(11 - 3)²) = √((-15)²+(8)²)
d = √(289) = 17
distance BC:
d = √((13 - 18)²+(15 - 3)²) = √((-5)²+(12)²)
d = √(169) = 13
Then, the distance in between Owen's house and school is 17 miles. The distance in between David's house and school is 13 miles.
Hence, David's house is 4 miles closer to school than the Owen's house.
answer: B)