I need to know which one is a u it rate. How and why u got that answer

Add 1/7 + -1/7 your answer should be reduced to its smallest form and should not be an improper fraction

Each of the walls of a room with square dimensions has been built with two pieces of sheetrock, a smaller one and a larger one. the length of all the smaller ones is the same and is stored in the variable small. similarly, the length of all the larger ones is the same and is stored in the variable large. write a single expression whose value is the total area of this room. do not use any method invocations.

Evaluate cos2θ for cosθ = square root of 3/2