Hey there, since we already have common denominators (the common denominators are 12) we are going to keep the denominator the same and add the numerators, 6+6=12. So, we have 12/12. And you asked to simplify it so 12/12=1. Therefore, 6/12+6/12=1. Hoped I helped. :)
Step-by-step explanation: You would change 6.10 into a fraction, which is 61/10. Then you would mulitply that and that number as a decimal would be 15.86.