Using commutativity and associativity of addition of rational numbers, express each of the following as a rational number:
(i) 25+73+−45+−13
(ii) 37+−49+−117+79
(iii) 25+83+−1115+45+−23
(iv) 47+0+−89+−137+1721
Evaluate each of the following: (i)23−35(ii)−47−2−3(iii)47−−5−7(iv)−2−59(v)−3−8−−27(vi)−413−−526(vii)−514−−27(viii)1315−1225(ix)−613−−713(x)724−1936(xi)563−−821