Answer:
620
Step-by-step explanation:
the sum of 126 and(-747) = 126+(-747)
= 126 -747 [positive plus negative=negative]
=-621
the sum of 135 and (-136) =135+ (-136)= 135 -136
=-1
subtract ⇒
-1-(-621) = -1+621 [negative plus negative=positive ]
=620
