How you read 0.312 and 0.5

How do you use the elimination method for this question? explain, because i really want to understand!

The first side of a triangle measures 5 in less than the second side, the third side is 3 in more than the first side, and the perimeter is 17 in. how long is the third side? if s represents the length of the second side, which of the following represents the length of the third side? s-5 ws-2 s+ 3 next question ask for turn it in

Victor is a mechanic who wants to ensure he has enough funds during his old age. which account will be of benefit to victor? a. checking account b. savings account c. money market account d. individual retirement account