Question 888735
{{{x^2y+xy^2+x^2+y^2=xy(x+y)+x^2+y^2}}}
{{{x^2y+xy^2+x^2+y^2=xy(x+y)+(x^2+2xy+y^2)-2xy}}}
{{{x^2y+xy^2+x^2+y^2=xy(x+y)+(x+y)^2-2xy}}}
Now substitute,
{{{x^2y+xy^2+x^2+y^2=b(a)+a^2-2b}}}
{{{highlight(x^2y+xy^2+x^2+y^2=a^2+ab-2b)}}}