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.
But let's actually figure it out. Get the denominator to a factor of 100. The most convenient one for this is 5, since that's also a factor of 15. Reduce the fraction with 3/3 (divide both the numerator and denominator by 3, in case that's unclear), and you get 3/5.eport Abuse. Method 1: Use long division to calculate 9Ã·15, then multiply the quotient by 100. 9Ã·15 = 0.6 0.6Ã100 = 60 So, 9 is 60% of 15. Method 2: Change 9/15 so the denominator is 100. The numerator is the percentage.