Question 353656
{{{(x+y)(x-y)+ x(x+y)=(x^2-xy+xy-y^2)+(x^2+xy)}}}
{{{(x+y)(x-y)+ x(x+y)=x^2-y^2+x^2+xy}}}
{{{(x+y)(x-y)+ x(x+y)=highlight(2x^2-y^2+xy)}}}