20-gallon gas tax can go 25 miles on 1 gallon if the tank is full at the beginning of a 725 miles trip how many times does the driver have to refill the gas tank

it would be 6xy and -16xy.

18

step-by-step explanation:

draw the shape and you will see that f and k are actually at adjacent vertices (points of the hexagon that are neighboring).   so find the distance between (1,2) and (4,2).   that is easy since (1,2) and (4,2) is just a vertical distance to count, which is 3.   it is a regular polygon which means all sides are congruent.   you have 6 sides (hexa) so multiply 6 by 3 to receive 18.