: Perform addition or subtraction of the resulting rational numbers. Example : If the problem is , the result is Problem 15.40: Comparing Values

This problem usually asks to find the value of an expression involving square roots.

The request for a guide on appears to be a search for homework solutions (GDZ) for an 8th-grade algebra textbook, likely by authors such as Mordkovich, which commonly use this numbering system. The ".dll" at the end of your query is likely a typo or an artifact of a file search, as Dynamic Link Libraries (.dll) are Windows system files and not related to math problems.

Dynamic link library (DLL) - Windows Client - Microsoft Learn

: Look for numbers that are perfect squares (e.g., Apply Root Properties : Use the property

, the equation has because a square root cannot be negative. Square Both Sides : If , square both sides to get