What is the key step for adding or subtracting unlike fractions?

To add or subtract unlike fractions, finding the lowest common denominator is essential. Unlike fractions are those that have different denominators, which means they cannot be combined directly. The process involves determining the smallest number that both denominators can divide into without leaving a remainder. This common denominator allows you to convert each fraction into an equivalent fraction that has the same denominator, enabling you to perform the addition or subtraction.

For example, if you are working with the fractions 1/3 and 1/4, the lowest common denominator would be 12. By converting each fraction—1/3 becomes 4/12 and 1/4 becomes 3/12—you can then easily add or subtract them to get the final result.

The other options, while they may relate to fractions in some way, do not address the specific requirement for adding or subtracting unlike fractions. The greatest common factor is more relevant for simplifying fractions rather than performing operations on them. Converting to decimals can work as a method but is not the most efficient or systematic approach for dealing with fractions. Inverting fractions pertains to reciprocal operations, which is unrelated to the process of addition or subtraction of unlike fractions. Thus, the key step lies in identifying and utilizing the lowest common denominator