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.
Example 2: Rationalize the denominator . Step 1: Multiply numerator and denominator by a radical that will get rid of the radical in the denominator. Since we have a cube root in the denominator, we need to multiply by the cube root of an expression that will give us a perfect cube under the radical in the denominator.