Name the property of multiplication illustrated by each of the following statements :
(i) −158×−127=−127×−158
(ii) (−23×79)×−95=−23×(79×−95)
(iii) −34×(−34×−56)+(−34×78)
(iv) −169×1=1×−169=−169
(v) −1115×15−11=15−11×−1115=1
(vi) −75×0=0
Re-arrange suitably and find the sum in each of the following :
(i)1112+−173+112+−252
(ii)−67+−56+−49+−157
(iii)35+73+95+−1315+−73
(iv) 413+−58+−813+913
(v)23+−45+13+25
(vi) 18+512+27+712+97+−516
Prove that:(i) 13+√7+1√7+√5+1√5+√3+1√3+1=1(ii) 11+√2+1√2+√3+1√3+√4+1√4+√5+1√5+√6+1√6+√7+1√7+√8+1√8+√9=2
Without adding find the sum
(i) 1 + 3 + 5 + 7 + 9
(ii) 1 + 3 + 5 + 7 + 9 + 11 + 13 + 15 + 17 + 19
(iii) 1 + 3 + 5 + 7 + 9 + 11 + 13 + 15 + 17 + 19 + 21 + 23