Okay just find something the bottom and the top number can be divided by. Like the first one 9/18. They are bithe dividable by 9 so 9÷9=1. 18÷9=2. Now put one back over two. 1/2. So your answer is one half. This is to help you learn how to do it I hope it helps.
If there are only two colors (let's say blue and red), here's what can happen:
sock #1 is blue
#2 is either blue or red. If blue, it matches #1 and you have a pair.
if red, go to #3
#3-either blue or red. If blue, matches #1. If red, matches #2.
OR sock #1 is red... then just reverse the colors. Basically, if you have three things that can only be in two groups, then even if two of them are different, the last one has to match one of them.
A perpendicular bisector cuts a line segment directly in half. a property of perpendicular bisectors is that any point on the line of the bisector will be equidistant (the same distance from) both end points.
Ex, If point X was 5 ft away from one endpoint, it would be 5 feet away from the other as well.
Yes because if you divide both, the numerator and denominator, by 7 it would simplify to 10/3, so they are equivalent.