Ответ:

[tex](a^{2} -y^{2} -x^{2} +2xy):\frac{a+y-x}{a+y+x}[/tex]=

=[tex](a^{2} -(y^{2} -2xy+x^{2}) )*\frac{a+y+x}{a+y-x}[/tex]=

=[tex](a^{2} -(y-x)^{2} )*\frac{a+y+x}{a+y-x}[/tex]=

=[tex](a-(y-x))*(a+(y-x))*\frac{a+y+x}{a+y-x}[/tex]=

=[tex](a-y+x)*(a+y-x)*\frac{a+y+x}{a+y-x}[/tex]=

=[tex](a-y+x)*(a+y+x)[/tex]=

=[tex](a+x)^{2} -y^{2} =a^{2} +2ax+x^{2} -y^{2}[/tex]

[tex]8.6^{2} +2*8.6*\frac{10}{3} -(11\frac{14}{15} )^{2} =(\frac{43}{5} )^{2}+2*\frac{43}{5}*\frac{10}{3} -(\frac{179}{15} )^{2}[/tex]=

=[tex]\frac{1849}{25} +2*43*\frac{2}{3} -\frac{32041}{225} =\frac{1849}{25} +\frac{172}{3} -\frac{32041}{225} =\frac{9847}{75} -\frac{32041}{225} =-\frac{100}{9} =-11\frac{1}{9}[/tex]