75 357 



s = 11 



s = l ^ 



s = l 

 s — n 



*4o. 2r„+,+^(-if(^J')22«r„_^,+i = 0. 



s = /i — 1 



-H. ^(-l)'(2s + i)3^+'7'n-s = -fî„-(-l)"(32n-2). 



.s- = 

 s = n 1 



43. ^(-1)'(^"27^)^''^«-^ = (^l)«-'(32"-'-2). 



s = 

 s = ni 



4:î. ^(-1)' (25 + 1)^''^' ^"-^ --= -ßn + (-1)"-^. 



s = U 



s = n-- l 



44. 7-„+i -^(-1)^^25^+2) ^''^' ^"-^ = -3£;„ + (-l)M. 



s = ü 

 s = n— 1 



■15. ^(-1)^(25 + 1)*''^"- = (-l)«-'(42"-l-22n-l). 



s = U 

 s=_n-l 



40. ^(-l)»(2"+2)^^^"-» = (-l)«-i(42n-i_22«-2). 



Ä = u 



S^Jl— 1 



47. 2nr„+^(-lf(^^^J)4-^^r„_s = (-l)"-i22"-i. 



S = 1 



s=_n— 1 



48. ^(-l)'(2s%)4''^'— = (-l)"-'22«-2. 



s = o 

 s == n— 1 



40. ^(-l)'(2s+î)^''^'^"-» = £n + (-l)"-*4(32n-i-2). 



S = U 



s = n— 1 



50. r,.+, -^(-1)^(25+2) ^''^' ^"-» = ^^" + (-DM (32«- 2). 



s = u 



s = n 



51. 2nr„+.+^(-l)»(2^+j)62^r„_.+i = tZ^(42n_22n). 



5 = 1 



S = n 



53. 2r,.+ ,+^(-l)»(2j)62»r„_,+, = (_l)n(42"+i-22"+3). 



46* 



