5*(1+x)^(15)=a_(0)+a_(1)x+.....+a_(15)x^(15)rArr sum_(r=1)^(15)r(a_(r))/(a_(r-1))=

(1 +x)^15 = a_0 + a_1x +…..+a_15 x^15 rArr sum_(r = 1)^15 r (a_r)/(a_(r - 1)) =

(1 +x)^15 = a_0 + a_1x +…..+a_15 x^15 rArr sum_(r = 1)^15 r (a_r)/(a_(r - 1)) =

If (1+x) ^(15) =a_(0) +a_(1) x +a_(2) x ^(2) +…+ a_(15) x ^(15), then the value of sum_(r=1) ^(15) r . (a_(r))/(a _(r-1)) is-

If (1+x) ^(15) =a_(0) +a_(1) x +a_(2) x ^(2) +…+ a_(15) x ^(15), then the value of sum_(r=1) ^(15) r . (a_(r))/(a _(r-1)) is-

(1+x+x^(2))^(8)=a_(0)+a_(1)x+.....+a_(16)x^(16) then a_(1)-a_(3)+a_(5)-a_(7)+......-a_(15)=

If (x^(2)+x+1)/(1-x) = a_(0) + a_(1)x+a_(2)x^(2)+"…." , then sum_(r=1)^(50) a_(r) equal to

If (x^(2)+x+1)/(1-x) = a_(0) + a_(1)x+a_(2)x^(2)+"…." , then sum_(r=1)^(50) a_(r) equal to

If (x^(2)+x+1)/(1-x) = a_(0) + a_(1)x+a_(2)x^(2)+"…." , the b sum_(r=1)^(50) a_(r) equal to

Let (1 + x + x^(2))^(n) = sum_(r=0)^(2n) a_(r) x^(r) . If sum_(r=0)^(2n)(1)/(a_(r))= alpha , then sum_(r=0)^(2n) (r)/(a_(r)) =