The value of 35+−76+25+−56 is ____.
Rearranging and grouping the numbers in pairs in such a way that each group contains a pair of rational numbers with same denominators, we have
35+−76+25+−56
=35+(−76+25)+−56
=35+(25+−76)+−56
[Since addition of rational numbers is commutative]
=35+25+−76+−56
=(35+25)+(−76+−56)
[Since addition of rational numbers is associative]
=3+25+(−7)+(−5)6=55+(−12)6=1+(−2)=−1