Question

what should be added to the sum of 13/15 and 27/20 to get 91/60​

Answer 1

$\frac{13}{15} + \frac{27}{20} + x = \frac{91}{60}\\\\\frac{52+81}{60} + x = \frac{91}{60} \\\\x = \frac{91}{60} - \frac{133}{60}\\\\x = \frac{-42}{60}$

this is the answer

Hope you have a great day

Peace