$\left(x+y-2\right)^{6}+\frac{1}{\left(x-y+7\right)^{5}}$

$6x\times \left(\frac{xy-y^{2}+7y}{x-y+7}\right)^{5}+6y\times \left(\frac{x^{2}-xy+7x}{x-y+7}\right)^{5}-12\times \left(\frac{xy-y^{2}+7y}{x-y+7}\right)^{5}-12\times \left(\frac{x^{2}-xy+7x}{x-y+7}\right)^{5}+20\left(xy\right)^{3}+15x^{2}y^{4}+15y^{2}x^{4}+360\left(xy\right)^{2}+x^{6}+y^{6}-120x^{2}y^{3}-120y^{2}x^{3}-60xy^{4}-60yx^{4}+240xy^{3}+240yx^{3}+60x^{4}+60y^{4}-480xy^{2}-480yx^{2}-160x^{3}-160y^{3}+480xy+240x^{2}+240y^{2}-192x-192y+64+\frac{1}{\left(x-y+7\right)^{5}}$