True, you can even test it out yourself. If the domain (x) is the same then it will be a vertical line. Like if you graphed (1,2) (1,4), (1,6) it will be a vertical line on your graph. I hope this helps!
The intersection of two sets A and B is defined as the set composed by the elements appearing in both A and B.
So, the intersection is

Because all the other numbers do not belong to both sets:
- 2, 3 and 7 belong to A alone
- 13, 15 and 17 belong to B alone
- 5 and 11 belong to both A and B
The distance formula between two points is d∧2=(x2-x1)∧2 + (y2-y1)∧2
The distance between Vista and Oceanside is
d1∧2=(-1-(-6))∧2+(6-2)∧2=(-1+6)∧2+4∧2=5∧2+16=25+16=41 => d=√41= 6.4
The distance between Oceanside and Alpena is
d2∧2=(0-(-1))∧2+(-1-6)∧2=1+(-7)∧2=1+49=50 => d2=√50=7.07
The distance between Vista and Alpena is
d3∧2=(0-(-6))∧2+(-1-2)∧2=36+9=45 => d3=√45= 6.7
Answer a) is Oceanside and Alpena
Answer b) is Vista and Oceanside
Good luck!!!
3 : 3,6,9,12,15,18,21,24,27,30
4 : 4,8,12,16,20,24,28,32,36
7: 7,14,21,28,35,42,49,56,63
9: 9,18,27,36,45,54,63,72,81