Verdict. The Microsoft Lumia 638 is an attractive budget friendly smartphone with the latest Windows OS and support for 4G LTE Cat4. It features a powerful Qualcomm Snapdragon processor but the lack of front camera is a big disappointment.
Steps. 1. Make sure that the denominators of every fraction that you're going to add or subtract are the same. 1  If the numbers are different, you can't add or subtract the fractions as-is.2  You can, however, perform the operations necessary to create fractions with like denominators, in which case you can add and subtract them.teps. 1. Make sure that the denominators of every fraction that you're going to add or subtract are the same. 1  If the numbers are different, you can't add or subtract the fractions as-is.
You can multiply the numerator and the denominator of a fraction by any nonzero whole number, as long as you multiply both by the same whole number! For example, you can multiply the numerator and the denominator by 3, as shown in part A above. But you cannot multiply the numerator by 3 and the denominator by 5.ultiplying the numerator and the denominator of a fraction by the same nonzero whole number will change that fraction into an equivalent fraction, but it will not change its value. Equivalent fractions may look different, but they have the same value. Let's look at some more examples of equivalent fractions. Example 5.