यदि `a_(1),a_(2),a_(3),a_(4)(1+x)^(n)` प्रसार के 4 क्रमागत के गुणांक पद है तो सिद्ध कीजिएः `(a_(1))/(a_(1)+a_(2))+(a_(3))/(a_(3)+a_(4))=2(a_(2))/(a_(2)+a_(3))`

Answer

` (a_1)/( a_1+ a_2) +(a_3) /( a_3+a_4)=2( a_2)/(a_2+a_3) `