If X={1,2,3,4,5,6,7,8}andY={11,13,15,17,19} then fill in the blank using symbol ∈or∉:
7_____X
Hence, 7 is an element of X
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
Fill in the blanks.
(i) (−317)+(−125)=(−125)+(.....)
(ii) −9+−218=(......)+(−9)
(iii) (−813+37)+(−134)=(......)+[37+(−134)]
(iv) −12+(712+−911)=(−12+712)+(.....)
(v) 19−5+(−311+−78)={19−5+(.....)}+−78
(vi) −167+.....=......+−167=−167
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
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