The equation of the base of an equilateral triangle is $x+y=2$ and its opposite vertex is $(2,1)$. If $m_1, m_2$ are the slopes of the other two sides and the length of its side is $a$, then $\left|m_1-m_2\right|+a \sqrt{2}=$

The triangle formed by the lines $2 x^2+x y-6 y^2=0$ and $x+y-1=0$ is

If $A(1,0), B(0,-2)$ and $C(2,-1)$ are three fixed points, then the equation of the locus of a point $P$ such that area of $\triangle P A B$ is equal to area of $\triangle P A C$ is