Is 6.610 an irrational number

1. what is the formula for finding the vertical distance between two points on a coordinate plane?

If you have the following equation, 2/3x+5/6-x=2-3/4x what would you multiply each term by to get rid of all the fractions

Ok a point t on a segment with endpoints d(1, 4) and f(7, 1) partitions the segment in a 2: 1 ratio. find t. you must show all work to receive credit.