Выражение : (a+b)^4-(a-b)^4/(a^2+b^2)*91/a+1/b)*(a+b)^2/a^2b^2

 \frac{(a+b)^4-(a-b)^4}{(a^2+b^2)*( \frac{91}{a}+ \frac{1}{b}) } * \frac{(a+b)^2}{a^2b^2} =\frac{(a+b)^2)a+b)^2-(a+b)(a-b)(a+b)(a-b)}{(a^2+b^2)*( \frac{91+a}{ab}) } * \frac{(a+b)^2}{a^2b^2} =  \frac{(a+b)^2-(a-b)^2}{(a+b)^2* \frac{91b+a}{ab} } * \frac{(a+b)^2}{a^2b^2} = \frac{(a+b)^2-(a+b)(a-b)}{(a+b)^2* \frac{91b+a}{ab} } * \frac{(a+b)^2}{a^2b^2} =\frac{(a+b)(a-b)(a+b)^2}{(a+b)^2* \frac{91b+a}{ab}*a^2b^2 }=  \frac{(a-b)^2}{ \frac{91b+a)a^2b^2}{ab} } =  \frac{(a-b)^2}{(91b+a)ab} =  \frac{a^2-2ab+b^2}{91ab62+a^2b} = \frac{ab( \frac{1}{b}+2+ \frac{1}{a} }{ab(91b+a)} = \frac{ \frac{1}{b} +2+\frac{1}{a} }{91b+a}=\frac{2+ \frac{a+b}{ab}}{91b+a}=\frac{(2ab+a+b)(91b+a)}{ab}=\frac{182ab^2+2a^2b+91ab+a^2+91b^2+ab}{ab} = \frac{ab(182b+2a+91+ \frac{a}{b} + \frac{91b}{a} +1 }{ab} =182b+2a+91+ \frac{a}{b} + \frac{91b}{a} +1=182b+2a+93+ \frac{a^2+91b^2}{ab} = 182ab^2+2a^2b+93ab+a^2+91b^2